The Bottom Line
Five supplements have robust clinical evidence for most people: Vitamin D3 + K2 (synergistic pair), Omega-3s (if you don't eat fatty fish twice weekly), Magnesium (50%+ of people are deficient), Creatine (one of the most researched supplements ever), and Ashwagandha (29% stress reduction, 15% testosterone increase). Everything else is either situational or requires more scrutiny.
The $150 Billion Problem
The supplement industry is largely unregulated. The FDA doesn't approve supplements before they hit shelves—they only step in after people get hurt. This means companies can make vague "structure/function" claims without proving anything works.
The Harsh Reality
The average American spends $56/month on supplements. Most of that money goes to products with minimal evidence, poor bioavailability, or underdosed formulations. This guide separates what actually works from expensive placebo.
Tier 1: The Essential Five
These supplements have overwhelming evidence from multiple meta-analyses and randomized controlled trials. Most people will benefit from at least some of these.
Vitamin D3 + K2 (The Synergistic Pair)
The most common deficiency in the developed world, with a critical co-factor
Why D3 Matters:
- 42% of Americans are deficient — rises to 82% in Black Americans and 70% in Hispanics due to melanin reducing UV synthesis
- 13% reduction in cancer mortality — BMJ 2019 meta-analysis of 52 RCTs (75,454 participants)
- Optimal blood level: 40-60 ng/mL — most people taking 1,000 IU still test deficient
Why K2 is Critical:
Vitamin D3 increases calcium absorption—but without K2, that calcium can deposit in arteries instead of bones. K2 (specifically MK-7) activates Matrix Gla Protein (MGP), the body's most potent inhibitor of arterial calcification.
- 3-year clinical study: 180μg MK-7 daily significantly improved arterial elasticity in post-menopausal women
- AVADEC study: K2 + D3 slowed coronary artery calcification progression in high-risk patients
Below 20 ng/mL: 40-90% increased mortality risk. Over 40% of Americans fall into this category.
Sweet Spot (40-60 ng/mL): Lowest all-cause mortality, optimal bone health, and reduced cancer risk.
Based on BMJ meta-analysis (2019) and systematic reviews showing J-shaped mortality curve with optimal levels at 40-60 ng/mL.
Key Studies:
- • BMJ 2019: Meta-analysis of vitamin D and mortality (52 RCTs, n=75,454)
- • Nutrients 2021: Vitamin K2 and arterial calcification review
- • Open Heart 2021: "Vitamin K2—a neglected player in cardiovascular health"
Recommended Dose
D3: 2,000-5,000 IU/day (test levels after 3 months)
K2 (MK-7): 100-200μg/day
Cost
~$12-18/month for quality D3+K2 combo
Omega-3 Fatty Acids (EPA/DHA)
Essential fats your body cannot produce
- 90%+ of Americans consume less than recommended 0.5g/day EPA+DHA from food (NHANES 2003-2008)
- Significant reduction in major cardiovascular events, MI, and all-cause mortality in meta-analyses
- DHA specifically decreases heart rate, blood pressure, and increases LDL particle size (less atherogenic)
Index below 4%: The average American sits here. 90% higher CHD mortality risk than optimal.
Index above 8%: Maximum cardioprotection. Common in Japan where fish consumption is high.
Source: Harris & von Schacky, Preventive Medicine 2004. The Omega-3 Index is now recognized as a reliable biomarker for cardiovascular risk.
Key Study:
Harris WS, von Schacky C. "The Omega-3 Index: a new risk factor for death from coronary heart disease?" Preventive Medicine, 2004. Established 8% as the cardioprotective threshold.
Recommended Dose
1-3g combined EPA/DHA daily
(Most capsules are 1g fish oil with ~300mg EPA/DHA—read the label)
Cost
~$10-15/month for quality fish oil
Magnesium
Cofactor in 300+ enzymatic reactions
- 50-68% of Americans don't meet the RDA through diet alone (NHANES 2003-2018)
- Critical for: ATP production, DNA synthesis, muscle/nerve function, blood glucose control, blood pressure regulation
- Low magnesium linked to: higher inflammation, insulin resistance, hypertension, depression
Form Matters: Bioavailability Comparison
Not all magnesium is created equal. Based on Uysal et al. 2018 study in rats:
Highest brain bioavailability (1.2x more brain accumulation), best for cognitive/anxiety support
High absorption, gentle on stomach, good for sleep and relaxation via GABA support
Highest overall AUC (absorption), good for energy and muscle function
Poor absorption (~4%), mostly used as laxative—avoid for supplementation
Taurate: 1.2x higher brain accumulation than other forms. Best for cognitive benefits.
Glycinate: Excellent absorption, includes calming glycine. Best for sleep.
Oxide: Only 4% absorbed. You're literally flushing money.
Malate: Highest overall absorption. Good for energy and muscle recovery.
Source: Uysal et al. "Timeline (Bioavailability) of Magnesium Compounds in Hours" - Biol Trace Elem Res 2018
Key Study:
Uysal N, et al. "Timeline (Bioavailability) of Magnesium Compounds in Hours: Which Magnesium Compound Works Best?" Biological Trace Element Research, 2018. Compared 10 magnesium forms.
Recommended Dose
200-400mg elemental magnesium daily
(Glycinate, Taurate, or Malate forms)
Cost
~$8-15/month for quality chelated forms
Creatine Monohydrate
The most researched supplement in history (500+ studies)
- Beyond muscle: Significant cognitive benefits, especially for older adults (66-76 years) and vegetarians
- Meta-analysis findings: Improves short-term memory and intelligence/reasoning (Avgerinos et al., 2018)
- Mechanism: Increases brain phosphocreatine, enhancing ATP regeneration during demanding cognitive tasks
Vegetarians see 25% memory boost: They have lower baseline creatine stores since it's mainly found in meat.
Older adults benefit most: 19% memory improvement. Brain creatine levels decline with age.
Young meat-eaters: Minimal cognitive benefit, but still helps with muscle and exercise performance.
Source: Avgerinos et al. "Effects of creatine supplementation on cognitive function" - Exp Gerontol 2018
Key Study:
Avgerinos KI, et al. "Effects of creatine supplementation on cognitive function of healthy individuals: A systematic review of randomized controlled trials." Experimental Gerontology, 2018.
Recommended Dose
3-5g daily (no loading phase needed)
Creatine monohydrate is the only proven form
Cost
~$5-8/month (one of the cheapest effective supplements)
Why supplement instead of food?
Food sources like beef and fish provide only 1-2g of creatine per day. To reach the effective dose of 3-5g daily, you'd need to eat extremely large amounts of meat (multiple steaks daily) or high-heat cooking destroys most creatine anyway. A cheap $5/month supplement provides consistent, reliable dosing that's impossible to achieve from diet alone.
Ashwagandha (KSM-66)
The most clinically studied adaptogen with 50+ RCTs
- 29% reduction in perceived stress and 19% reduction in serum cortisol in multi-continent study (1,000+ participants)
- 14.7% greater testosterone increase vs placebo in aging males (8-week RCT)
- 43% improvement on Hamilton Anxiety Scale — clinically significant for anxiety reduction
- Cognitive benefits: Improved executive function, memory, information processing speed, and concentration
Why This Matters:
Chronic stress elevates cortisol, which impairs memory consolidation, reduces testosterone, disrupts sleep, and promotes visceral fat storage. Ashwagandha addresses the root cause rather than just symptoms. The testosterone increase alone (15%) is more than most "testosterone boosters" can legitimately claim—and those cost 3-4x more.
Key Studies:
- • Multi-continent KSM-66 study: 29% stress reduction, 19% cortisol reduction (n=1,000+)
- • 8-week RCT in aging males: 14.7% greater testosterone vs placebo
- • Systematic review: Positive effects on testosterone confirmed across multiple studies
Recommended Dose
300-600mg daily (KSM-66 or Sensoril extracts)
Take consistently for 8+ weeks for full effects
Cost
~$10-15/month for quality KSM-66 extract
Tier 2: Situational Supplements
These have good evidence but are most beneficial for specific populations or situations.
Zinc
Who needs it: Men (testosterone support), frequent illness, vegetarians, elderly
What it does:
Essential for immune function, protein synthesis, wound healing, and cell division. Directly supports testosterone production and sperm quality.
- • 2022 systematic review (38 studies): Serum zinc positively correlates with testosterone; supplementation improves T levels in deficient men
- • Clinical trial: Men consuming only 1.4mg Zn/day saw testosterone drop from 26.9 to 21.9 nmol/L
- • Deficiency signs: Hair loss, frequent infections, poor wound healing, loss of appetite
⚠️ Important Warning:
Excess zinc (150mg+) depletes copper, causing neurological problems. Always take copper (1-2mg) if supplementing zinc long-term above 25mg/day.
Dosing:
• 15-30mg/day (picolinate form best absorbed)
• Take with food to avoid nausea
• Don't exceed 40mg without blood testing
Source: Journal of Trace Elements in Medicine and Biology, 2022
CoQ10 (Ubiquinol)
Who needs it: Anyone on statins, adults 40+, those with heart conditions
What it does:
Critical cofactor in mitochondrial ATP production (cellular energy). Acts as potent antioxidant and membrane stabilizer. Natural production declines 50%+ after age 40.
- • Randomized clinical trial: 100mg/day reduced statin-related muscle symptoms in 75% of patients
- • Q-SYMBIO trial: Reduced major cardiac events in heart failure patients
- • Statins block CoQ10 synthesis via the mevalonate pathway—supplementation replaces what statins deplete
- • Ubiquinol vs ubiquinone: Ubiquinol is 3-4x better absorbed (the reduced, active form)
Dosing:
• 100-200mg/day ubiquinol (take with fat for absorption)
• Morning with breakfast optimal
• If on statins: mandatory supplementation
Source: Medical Science Monitor, 2014; JACC Heart Failure, 2014
B12 (Methylcobalamin)
Who needs it: Vegans/vegetarians, elderly, those on metformin or PPIs
What it does:
Essential for neurological function, red blood cell formation, DNA synthesis. Required for myelin sheath maintenance (nerve insulation).
- • Up to 40% of adults over 60 have B12 deficiency (Journal of Neuropsychiatry)
- • Deficiency causes irreversible nerve damage if prolonged—symptoms include numbness, tingling, memory loss, fatigue
- • Vegans have NO dietary B12 sources (only found in animal products)
- • Metformin and PPIs block B12 absorption—supplementation mandatory
💡 Testing:
Serum B12 below 300 pg/mL indicates deficiency. Check every 1-2 years if over 50 or on medications that deplete B12.
Dosing:
• 500-1000mcg/day methylcobalamin (not cyanocobalamin)
• Sublingual or oral equally effective
• Virtually no upper limit—excess excreted
Source: Journal of Neuropsychiatry and Clinical Neurosciences
Vitamin C
Who needs it: Smokers, high stress, athletes, immune support
What it does:
Essential for collagen synthesis, powerful antioxidant, immune support. Water-soluble so body excretes excess—very safe even at high doses.
- • Meta-analysis: 1g/day reduced cold symptom severity by 15% (BMC Public Health, 2023)
- • Regular supplementation (200mg+) shortened cold duration by 9.4% in general population
- • High doses (6-8g/day) may be twice as effective as 3-4g/day for severe cold symptoms
- • Smokers need 35mg/day MORE than non-smokers due to increased oxidative stress
Dosing:
• 500-2000mg/day split into 2-3 doses (better absorption)
• During illness: up to 6-8g/day divided every 2-3 hours
• Buffered or liposomal forms reduce GI upset
• Side effects: Only GI upset/diarrhea at very high doses
Source: BMC Public Health, 2023
Potassium Citrate
Who needs it: High sodium diet, hypertension, athletes with cramping
What it does:
Regulates fluid balance, muscle contractions, nerve signals, and blood pressure. Works antagonistically to sodium—high K/Na ratio is protective.
- • Randomized crossover trial: Both potassium citrate and chloride significantly lowered BP vs baseline
- • Dose-response meta-analysis showed U-shaped relationship—adequate intake beneficial, excess risky
- • Most Americans get only 2,600mg/day vs recommended 3,400-4,700mg
- • Food sources best: bananas (422mg), potatoes (897mg), spinach (558mg per cup)
⚠️ Caution:
Don't supplement if on ACE inhibitors, ARBs, or potassium-sparing diuretics—can cause dangerous hyperkalemia (high potassium).
Dosing:
• 300-500mg/day supplemental (citrate form)
• Get 3,000+ mg from food daily
• Take with food, never on empty stomach
Source: American Journal of Clinical Nutrition
Iodine
Who needs it: Low seafood/iodized salt intake, hypothyroidism risk, pregnant women
What it does:
Essential component of thyroid hormones (T3/T4) which regulate metabolism, energy, brain development. Deficiency during pregnancy causes irreversible cognitive impairment in fetus.
- • Clinical trial: 150mcg/day for 24 weeks significantly decreased thyroglobulin (iodine status marker)
- • Severe deficiency causes goiter (enlarged thyroid) as body tries to capture more iodine
- • Pregnancy: Critical for fetal brain development—deficiency increases risk of cretinism
- • WHO/UNICEF recommend 150mcg/day for pregnant women in areas with limited iodized salt
⚠️ Important Warning:
Excessive iodine (>1,100mcg) can cause thyroid dysfunction. Pregnant women especially sensitive—fetal thyroid vulnerable to excess.
Dosing:
• 150-300mcg/day (from kelp or potassium iodide)
• Check if your salt is iodized—may not need supplementation
• Upper limit: 1,100mcg/day
Source: European Journal of Endocrinology; WHO/UNICEF
Iron (Bisglycinate)
Who needs it: Pre-menopausal women, athletes (esp. female), vegetarians/vegans
What it does:
Essential for hemoglobin production (oxygen transport), energy metabolism, immune function. Deficiency causes anemia, fatigue, impaired athletic performance.
- • Up to 60% of female athletes are iron deficient (Sports Medicine, 2024)
- • Meta-analysis: Oral iron (16-100mg elemental iron) for 6-8 weeks increases serum ferritin, especially if baseline <12 µg/L
- • Bisglycinate is 2.5-3.4x more bioavailable than ferrous sulfate with 80% fewer GI issues
- • Female athletes with deficiency: impaired endurance, reduced work capacity, decreased energy efficiency
💡 Testing Required:
Test ferritin BEFORE supplementing. Excess iron is toxic (oxidative damage). Target: 30-50 µg/L for women, 50-100 µg/L for men.
Dosing:
• 18-30mg/day elemental iron (women), 8-10mg (men—rarely needed)
• Take with vitamin C (enhances absorption 3-4x)
• Avoid with coffee, tea, calcium (block absorption)
• Empty stomach for best absorption, with food if GI upset
Source: Sports Medicine, 2024
L-Theanine
Who needs it: High stress, caffeine-sensitive, anxiety, poor sleep quality
What it does:
Amino acid found in tea. Crosses blood-brain barrier, mimics GABA (calming neurotransmitter), increases alpha brain waves (relaxed alertness). Synergizes with caffeine.
- • Clinical studies: Significantly reduces psychiatric symptoms in anxiety disorders, schizophrenia, and ADHD
- • GAD study: 450-900mg didn't beat placebo for overall anxiety, but improved sleep satisfaction
- • With caffeine: Promotes "calm alertness"—reduces jitters while maintaining focus
- • Increases dopamine, serotonin, and GABA—without drowsiness
Dosing:
• 100-400mg/day
• Sweet spot: 200mg with coffee (2:1 caffeine to L-theanine ratio)
• For sleep: 200mg 30-60 minutes before bed
• Very safe—no known side effects at recommended doses
Source: Journal of Clinical Psychiatry, 2019
Tongkat Ali
Who needs it: Men seeking testosterone optimization, stress reduction
What it does:
Malaysian herb (Eurycoma longifolia) that increases free testosterone by reducing sex hormone-binding globulin (SHBG). Also lowers cortisol (stress hormone).
- • 2012 clinical trial (76 men): 90.8% achieved normal testosterone levels after 1 month on 200mg daily (up from 35.5%)
- • Typical doses: 200-400mg standardized extract daily
- • Also shown to reduce cortisol and improve mood/stress resilience
💰 Cost-Benefit Analysis:
The catch: ~$25-35/month. Ashwagandha provides similar testosterone benefits (14.7% increase) PLUS superior cortisol reduction for half the price (~$10-15/month). Unless you've tried Ashwagandha without results, it's the better value.
Dosing:
• 200-400mg/day standardized extract (look for 100:1 or 200:1 ratio)
• Take with food
• Verdict: Works, but not as cost-effective as Ashwagandha
Source: Journal of the International Society of Sports Nutrition, 2012
Mixed Evidence: Proceed with Caution
These supplements have some promising research but also conflicting results, limited human data, or benefits that only appear in very specific contexts. May be worth trying if you have specific goals, but don't expect miracles.
L-Citrulline (Nitric Oxide Booster)
The promise: Improved blood flow, better exercise performance, cardiovascular health, erectile dysfunction
- • How it works: Converted to L-arginine in the body, boosting nitric oxide production (vasodilation)
- • For cardiovascular: Beetroot juice shows stronger evidence—improves blood pressure and blood flow in postmenopausal women; lower oxygen cost during exercise
- • For ED: Limited human data; studies on L-arginine show mixed results (meta-analysis of 10 RCTs showed debatable efficacy)
- • Dose: 2.4-6g daily; beetroot juice 250-500ml daily for cardiovascular benefits
Source: British Journal of Nutrition, 2023; Journal of Sexual Medicine, 2022
💡 Better to use as beetroot juice for cardiovascular benefits; L-citrulline for ED shows promise but needs more research
Curcumin (with Piperine)
The promise: Anti-inflammatory, joint pain relief, potential cognitive benefits
- • The problem: Curcumin has extremely poor bioavailability (~75% excreted unchanged in feces)
- • The fix: Piperine (black pepper extract) can increase bioavailability by up to 2,000% by inhibiting liver metabolism
- • Clinical data: Mixed results—one study found no cognitive effects even with piperine; another showed significant improvements
- • Dose: 500-1000mg curcumin with 20mg piperine (or look for specialized formulations like CurcuWIN, BCM-95)
Source: Planta Medica, 1998; Journal of Neuroscience Research, 2020
💡 Worth trying for joint pain or inflammation, but ONLY with piperine or enhanced formulations
Collagen Peptides
The promise: Skin hydration, joint pain relief, anti-aging
- • 2023 meta-analysis: Significant improvements in knee osteoarthritis pain and function
- • Some evidence for improved skin hydration and elasticity (modest effect sizes in most studies)
- • The skepticism: Collagen is broken down into amino acids during digestion—no guarantee it rebuilds as collagen in your skin
- • Dose: 10-15g daily for joint benefits; 2.5-5g for skin
Source: Clinical and Experimental Rheumatology, 2023
💡 Worth trying for joint pain (good evidence); skin benefits are plausible but less certain
Resveratrol
The promise: Longevity, cardiovascular health via Sirtuin activation
- • The hype: Based on studies showing it activates longevity genes (Sirtuins) and extends lifespan in yeast and worms
- • The reality: Meta-analysis found no significant impact on Sirtuin levels in humans overall
- • Subgroup finding: Significant Sirtuin increase only with interventions <12 weeks
- • Some benefit for cardiovascular health if you're already at risk
- • Dose: 150-500mg/day
Source: Nutrients, 2023; Circulation Research, 2020
💡 Overhyped for longevity; may help with cardiovascular health if you're already at risk
Anthocyanin/Berry Extract
The promise: Cardiovascular health, cognitive function, antioxidant replacement for fresh berries
- • 2025 umbrella review: Meta-analyses show anthocyanins reduce cardiovascular disease risk and improve lipid profiles (lower LDL-C, triglycerides; higher HDL-C)
- • Cognitive benefits: 2024 meta-analysis found improvements in short-term memory, executive function, and mood in some studies—but not statistically significant overall due to study heterogeneity
- • The major problem: Extremely poor bioavailability—only 0.004-5% absorption, with most excreted within 4 hours
- • Best source: Elderberry extract shows 5-6x better absorption than blackcurrant juice
- • Dose: 300-500mg anthocyanins daily (standardized extract)
Source: Food & Function, 2025; Nutrients in Practice, 2024; American Journal of Clinical Nutrition, 2005
💡 Better option: Buy frozen berries—they're cheaper, provide fiber, and have better bioavailability than extracts. Only supplement if fresh/frozen berries are truly unavailable.
Glutamine
The promise: Gut health, muscle recovery, immune function
- • 2024 meta-analysis: No significant effect on gut permeability overall
- • Exception: High doses (>30g/day) for <2 weeks showed reduced intestinal permeability
- • Athletic performance: Some benefit for weight reduction and immune function at doses >200mg/kg body weight
- • Reality check: Your body produces 40-80g of glutamine daily—supplementation only helps in extreme stress (burns, critical illness, intense training)
- • Dose: 5-10g post-workout (or 30g+ for gut issues under medical supervision)
Source: European Journal of Clinical Nutrition, 2024
💡 Unnecessary for most people; may help endurance athletes or those with gut issues
Probiotics (Generic)
The promise: Gut health, immune function, mood improvement
- • The problem: Probiotic efficacy is both strain-specific AND disease-specific
- • Meta-analyses: Pooling different probiotic types leads to misleading conclusions
- • Generic "10 billion CFU multi-strain" products may contain strains that don't help your specific issue
- • What works: Specific strains for specific conditions (e.g., Lactobacillus rhamnosus GG for traveler's diarrhea; VSL#3 for IBS)
- Many probiotic bacteria don't survive stomach acid or colonize your gut long-term
Source: Frontiers in Medicine, 2018; The Lancet eClinicalMedicine, 2021
💡 Don't waste money on generic probiotics. Choose research-backed strains for your specific health goal, or just eat fermented foods
Biotin (Vitamin B7)
Heavily marketed for hair, skin, and nails. A cofactor for five carboxylase enzymes in metabolism. True deficiency is rare but can occur with pregnancy, prolonged antibiotics, or certain genetic conditions.
The Evidence Gap:
Despite massive popularity, scientific evidence is surprisingly weak. A 1966 double-blind study showed no difference between biotin and placebo for hair growth in women with diffuse alopecia. Multiple recent reviews conclude there's limited high-quality evidence supporting biotin for hair/nail health in people without deficiency.
When It Works:
If you have confirmed biotin deficiency (rare), brittle nail syndrome, or uncombable hair syndrome, supplementation helps. Also beneficial during pregnancy/breastfeeding, with chronic alcohol use, or on certain medications that deplete biotin.
Important Warning:
High-dose biotin (≥5,000 mcg) can interfere with lab tests including troponin (heart attack marker) and thyroid hormones, potentially causing false positives/negatives. Stop 72 hours before blood work.
Verdict:
If you eat eggs, nuts, and whole grains regularly, you're probably getting enough. Worth trying for 3 months if you have brittle nails or thinning hair, but don't expect miracles. Far better evidence for collagen peptides for these concerns.
What to Approach with Caution
These aren't necessarily useless—but they're often overhyped, overpriced, or unnecessary for most people.
Multivitamins: It Depends
Cheap Synthetic Multivitamins (Skip These)
Most drugstore multivitamins use cheap synthetic forms (cyanocobalamin B12, folic acid instead of folate, oxide forms of minerals) with poor bioavailability.
- • 2018 meta-analysis: No association between MVM use and CVD mortality, CHD mortality, or stroke (Circulation, 2018)
- • 2024 JAMA study (390,124 participants, 20+ years): Multivitamin users had 4% higher mortality risk than non-users
- • No reduction in all-cause mortality or disease prevention across multiple large cohort studies
Source: JAMA Network Open, 2024; Circulation: Cardiovascular Quality and Outcomes, 2018
Food-Based Multivitamins (Worth Considering)
Whole-food sourced multivitamins (Garden of Life, MegaFood, New Chapter) contain nutrients bound to food matrices with natural co-factors. These have better bioavailability and contain the synergistic compounds found in real food. Not equivalent to whole foods, but a better insurance policy than synthetics.
Cost: $30-50/month | Verdict: Reasonable for those with dietary gaps, but targeted supplements are usually more effective
Calcium Supplements (Usually Skip)
Most people can get adequate calcium from diet (dairy, leafy greens, fortified foods). Supplementation has questionable benefits and real risks.
- • JAMA meta-analysis (33 RCTs): No significant reduction in hip, vertebral, or total fractures with calcium ± vitamin D in community-dwelling adults
- • Women's Health Initiative: Calcium + D increased hip bone density but didn't reduce fractures and increased kidney stone risk
- • Cardiovascular concern: Meta-analyses show 15-20% increased risk of myocardial infarction with calcium supplementation
- • Common GI side effects (constipation, bloating)
May Be Worth It For:
- • Diagnosed osteoporosis (under medical supervision with vitamin D + K2)
- • Severe dietary deficiency (vegans avoiding fortified foods, lactose intolerant without alternatives)
- • Postmenopausal women with multiple risk factors (only with doctor guidance)
Better approach: Get 1,000-1,200mg daily from food sources. 1 cup milk = 300mg, 1 cup Greek yogurt = 200mg, 1 cup cooked collard greens = 268mg.
Source: JAMA Network Open, 2018; NEJM, 2006; Heart Journal meta-analysis, 2012
Definite Skips
BCAAs
2025 systematic review: Leucine supplementation does not confer significant benefits in muscle growth, strength, or recovery in healthy trained adults.
Medicine & Science in Sports & Exercise: High-dose leucine doesn't enhance gains in young resistance-trained males who eat adequate protein.
Pointless if you eat adequate protein. Whey protein is cheaper and more effective because it contains ALL essential amino acids.
Source: Journal of the American College of Nutrition, 2025
Fat Burners
Yes, they increase metabolic rate (~200 kcal/day)—but that's mostly from caffeine. A cup of coffee costs $0.20 vs $40/month for fat burners. The proprietary blends hide that you're paying 200x markup for caffeine plus underdosed "thermogenic" herbs with no clinical backing.
Tongkat Ali (Eurycoma longifolia)
The Evidence: 2012 clinical trial with 76 men with low testosterone showed impressive results—only 35.5% had normal T levels before treatment, but 90.8% achieved normal testosterone levels after just one month on 200mg daily.
The Catch: While the clinical data is real, Tongkat Ali costs ~$25-35/month for quality extract (LJ100 or other standardized forms). Ashwagandha provides similar testosterone benefits (14.7% increase) PLUS cortisol reduction (19%), stress reduction (29%), and anxiety improvement (43%) for $12/month.
Dosage: 200-400mg standardized extract daily
💡 Verdict: Works, but Ashwagandha gives you more benefits for less money. Save Tongkat Ali for stacking if Ashwagandha alone isn't enough.
Fadogia Agrestis
The Evidence: Zero human clinical trials. None. Despite decades of traditional use in Nigeria, not a single published human study exists. Animal research shows promise for increasing luteinizing hormone (LH), but we have no idea if this translates to humans or what the safe dosage is.
The Risk: No standardization, no long-term safety data, and you're essentially beta-testing on yourself. Popular in bodybuilding circles, but that's not the same as clinical validation.
⚠️ Verdict: Skip until we have human data. Don't pay $20/month to be a guinea pig when proven alternatives exist.
"Testosterone Boosters"
Most are garbage. Exception: Ashwagandha (see Tier 1). Tribulus, D-aspartic acid, etc. have minimal evidence. If you want real results, get your levels tested and address lifestyle factors first.
Detox Products
Your liver and kidneys are your detox system. No supplement "cleanses" anything. These are pure marketing.
Cheap Vitamin Forms to Avoid
Not all supplement forms are equal. These cheap compounds have poor bioavailability and can even be problematic for some people:
Quick Reference - Skip These Forms:
Folic Acid
Synthetic form that requires conversion to methylfolate (5-MTHF). 40-60% of people have MTHFR gene variants that impair this conversion, leading to unmetabolized folic acid building up in the blood. This can block folate receptors and potentially mask B12 deficiency.
✓ Use instead: Methylfolate (5-MTHF) or Folinic Acid
Cyanocobalamin (B12)
Synthetic B12 containing a cyanide molecule that must be detoxified. Requires conversion to methylcobalamin or adenosylcobalamin. Natural forms are bioidentical to what your body produces and don't need conversion. While the cyanide amount is tiny and generally safe, why choose a form that requires extra metabolic steps?
✓ Use instead: Methylcobalamin or Adenosylcobalamin
Vitamin D2 (Ergocalciferol)
Plant-derived form that's 40% less effective at raising blood levels of 25(OH)D compared to D3. Meta-analysis of RCTs showed D3 increased levels by 10.39 nmol/L more than D2. Why take something objectively inferior?
✓ Use instead: Vitamin D3 (Cholecalciferol)
Pyridoxine HCl (B6)
Inactive form that requires liver conversion to P5P (pyridoxal-5-phosphate). People with liver issues, MTHFR mutations, or metabolic disorders can't convert it efficiently. Studies show P5P increases plasma levels 60% more than pyridoxine HCl.
✓ Use instead: P5P (Pyridoxal-5-Phosphate)
Magnesium Oxide
Only 4% bioavailability. Commonly causes digestive distress and diarrhea because it's poorly absorbed. It's the cheapest form, which is why it's in 90% of drugstore multivitamins. You're literally flushing your money down the toilet.
✓ Use instead: Magnesium Glycinate, Taurate, or Threonate
Zinc Oxide
~50% lower absorption than other zinc forms. Often causes nausea when taken on an empty stomach. Another cheap filler found in low-quality multivitamins alongside magnesium oxide.
✓ Use instead: Zinc Picolinate, Citrate, or Bisglycinate
Calcium Carbonate
Requires stomach acid for absorption—problematic for 15 million Americans taking PPIs or acid reducers. Calcium citrate is absorbed 22-27% better and doesn't require stomach acid. Carbonate also only contains 40% elemental calcium vs citrate's more efficient absorption.
✓ Use instead: Calcium Citrate or Calcium Malate
Ferrous Sulfate (Iron)
The most common iron supplement, but causes severe GI side effects (nausea, constipation, black stools) that kill compliance. Ferrous bisglycinate is 2.5-3.4x more bioavailable with minimal GI symptoms. Worth the slight price increase if you actually take it consistently.
✓ Use instead: Ferrous Bisglycinate (Chelated Iron)
Synthetic Vitamin E (dl-alpha-tocopherol)
Half the molecules are in the wrong orientation (mirror images your body can't use). Natural d-alpha-tocopherol has 197-252% better bioavailability in clinical studies. The "dl-" prefix is your warning sign it's synthetic junk.
✓ Use instead: d-alpha-tocopherol (natural) or Mixed Tocopherols
Vitamin K1 (Phylloquinone) Alone
K1 has low bioavailability despite being 75-90% of dietary K intake. More importantly, K1 primarily supports blood clotting while K2 (MK-7) directs calcium to bones and away from arteries. Studies show 180μg MK-7 daily significantly increases carboxylated osteocalcin (bone building marker) while reducing undercarboxylated osteocalcin.
✓ Use instead: Vitamin K2 (MK-7) - especially if taking D3
Omega-3 Ethyl Esters (EE Form)
The cheapest fish oil form with significantly lower bioavailability than triglyceride forms. Clinical trials show re-esterified triglycerides (rTG) deliver up to 3x higher plasma EPA+DHA levels. ECLIPSE II study confirmed free fatty acid forms have superior absorption on low-fat diets. EE forms are used because they're cheaper to manufacture—not because they work better.
✓ Use instead: Triglyceride (TG) or Re-esterified Triglyceride (rTG) fish oil
Plain Curcumin (No Absorption Enhancer)
Curcumin has extremely poor bioavailability—75% is excreted unchanged in feces. Clinical studies show piperine (black pepper extract) can increase bioavailability by up to 2,000% by inhibiting glucuronidation. Other delivery systems (liposomal, phytosome, nanoemulsion) also dramatically improve absorption. Plain curcumin powder is basically money down the drain.
✓ Use instead: Curcumin + Piperine, Meriva (phytosome), or Longvida (lipidated)
Real Talk: Check Your Supplement Labels NOW
If your supplement has cyanocobalamin, folic acid, magnesium oxide, dl-alpha-tocopherol, or omega-3 ethyl esters listed, you bought the cheapest possible ingredients. The manufacturer optimized for profit margins, not your health. Quality forms typically cost just $5-15 more per month but deliver 2-4x better absorption. Stop wasting money on supplements you're literally peeing out.
The Real Cost Breakdown
Evidence-Based Stack: ~$56/month
- • Vitamin D3+K2: $15/mo
- • Omega-3 rTG fish oil: $15/mo
- • Creatine Monohydrate: $6/mo
- • Magnesium Glycinate: $12/mo
- • Ashwagandha KSM-66: $12/mo
Typical Waste Stack: ~$125/month
- • Premium Multivitamin: $15/mo
- • Collagen Peptides: $25/mo
- • Tongkat + Fadogia stack: $48/mo
- • BCAAs: $30/mo
- • Fat Burner: $40/mo (just drink coffee)
The Evidence-Based Stack
Monthly Cost:
- • D3 + K2 combo: ~$15
- • Omega-3 (quality fish oil): ~$12
- • Magnesium (glycinate/taurate): ~$12
- • Creatine monohydrate: ~$6
- • Ashwagandha (KSM-66): ~$12
- Total: ~$57/month
What You Get:
- • Reduced cancer mortality risk
- • Cardiovascular protection
- • Improved bone and arterial health
- • Enhanced cognition and memory
- • Lower stress and cortisol
- • Optimized testosterone (men)
- • Better sleep quality
Compare this to the average American spending $56/month on supplements—often a random assortment of poorly-absorbed multivitamins and overhyped products with no evidence.
Quality Over Quantity
The supplement industry wants you to believe you need 20 different pills. The research says otherwise. Focus on fixing actual deficiencies with evidence-based supplements, and spend the savings on whole foods.