Food first, always. Supplements fill verified gaps and provide targeted ergogenic support — they do not replace a nutrient-dense diet.

21.1 The Evidence Tier System

All supplements in this chapter are classified by evidence quality:

21.2 Tier 1 Supplements — Strong Evidence

Creatine Monohydrate

• What it does: Replenishes phosphocreatine in muscle cells — the immediate energy currency for short, explosive efforts (0–10 seconds). Increases power output, strength gains, high-intensity work capacity, and — importantly — lean mass retention during caloric restriction.
• Cognitive benefit: Emerging strong evidence for creatine's role in brain energy metabolism — improvements in memory, processing speed, and cognitive fatigue, especially under sleep deprivation and in vegetarians/vegans (who have no dietary creatine source).
• Dose: 3–5g/day monohydrate; no loading phase required. Loading (20g/day for 5–7 days) merely saturates muscle stores faster — same endpoint either way.
• Timing: Irrelevant; daily consistency matters more than timing.
• Safety: One of the most studied supplements in existence. Decades of research show no adverse effects on renal function in healthy individuals. Stay hydrated.
• Who benefits most: Strength athletes, team sport athletes, vegetarians/vegans, older adults (muscle + cognitive protection), anyone in caloric deficit.

Protein Supplementation (Whey, Casein, Plant-Based)

• What it does: Convenient dietary protein source to meet daily targets — not a magical anabolic substance.
• Whey protein: Rapidly digested; high leucine content; ideal post-workout for MPS stimulation.
• Casein protein: Slowly digested (6–8 hours); ideal pre-sleep to sustain overnight MPS and reduce muscle catabolism.
• Plant-based blends (pea + rice): Combined amino acid profile approaches whey; appropriate for vegan/dairy-intolerant populations; lower leucine content — increase dose by ~10–15%.
• Dose: As needed to meet daily protein target (1.6–2.4g/kg/day from all sources).

Omega-3 (EPA + DHA)

• What it does: Anti-inflammatory; reduces triglycerides; supports cardiovascular, brain, and joint health; improves muscle protein synthesis response.
• Dose: 2–3g combined EPA+DHA per day. Algae-based DHA+EPA for vegans.
• Form: Triglyceride form > ethyl ester form for bioavailability. Take with the largest meal of the day.
• Who needs it: Most people in industrialized diets with high omega-6:omega-3 ratios.

Vitamin D3 (+ K2)

• What it does: Vitamin D is technically a hormone precursor. Deficiency (> 40% of the global population) is associated with impaired immune function, reduced testosterone, insulin resistance, mood disorders, and muscle weakness.
• K2 (MK-7): Directs calcium to bones rather than arterial walls — important co-factor when supplementing D3 at meaningful doses.
• Dose: 2,000–5,000 IU D3/day depending on baseline serum 25-OH-D level. Test before and after supplementing. Target serum level: 40–60 ng/mL.
• Timing: With a fat-containing meal (fat-soluble vitamin).

Magnesium

• What it does: Cofactor in 300+ enzymatic reactions. Critically involved in: muscle contraction and relaxation, sleep quality (GABA receptor modulation), insulin signaling, blood pressure regulation, and cortisol management.
• Forms matter significantly:
  • Magnesium Threonate: Blood-brain barrier penetration; best for sleep and cognitive function
  • Magnesium Glycinate: Well-absorbed; good for anxiety, sleep, and general repletion
  • Magnesium Citrate: Good absorption; mild laxative effect at higher doses
  • Magnesium Oxide: Poor absorption (~4%); avoid
• Dose: 300–400mg elemental magnesium/day; taken in the evening.

21.3 Tier 2 Supplements — Moderate Evidence

Caffeine

• What it does: Adenosine receptor antagonist — blocks the accumulation of sleep pressure and increases alertness, focus, and perceived exertion tolerance. Most extensively studied ergogenic aid in sports science.
• Performance effects: Improves endurance performance, strength output, reaction time, and mood. Acutely effective for both aerobic and anaerobic performance.
• Dose: 3–6mg/kg body weight, 30–60 minutes pre-exercise. At 80kg: 240–480mg.
• Tolerance and cycling: Adenosine receptor upregulation causes tolerance in 2–3 weeks of daily use. Cycle use for performance: 5 days on / 2 days off, or reserve high doses for priority training sessions.
• Cautions: Half-life of 5–7 hours — avoid after 2 PM if sleep is a priority. Worsens anxiety in sensitive individuals. Avoid during late pregnancy.

Beta-Alanine

• What it does: Precursor to carnosine — a muscle buffering agent that delays acidosis during high-intensity efforts lasting 60–240 seconds. Meaningful benefit for: sprinting, HIIT, circuit training, high-rep sets.
• Dose: 3.2–6.4g/day; split into doses of 0.8–1.6g to minimize tingling (paresthesia). Takes 4 weeks to saturate muscle carnosine stores.
• Who benefits: Athletes with sustained high-intensity efforts; minimal benefit for pure strength or very short/very long efforts.

Citrulline Malate

• What it does: Increases arginine bioavailability → stimulates nitric oxide production → vasodilation → improved blood flow to working muscles ("pump"), reduced fatigue, improved endurance performance.
• Dose: 6–8g citrulline malate 30–60 minutes pre-exercise. L-citrulline alone: 3–4g.

Zinc

• What it does: Essential cofactor for testosterone synthesis, immune function, and protein synthesis. Common deficiency in athletes (lost through sweat) and plant-based eaters (phytates reduce absorption).
• Dose: 15–25mg/day zinc picolinate or bisglycinate. Avoid > 40mg/day long-term (copper depletion).
• Note: ZMA (zinc + magnesium + B6) is a common combined formula; evidence is modest but both zinc and magnesium are individually justified.

Berberine

• What it does: Activates AMPK (AMP-activated protein kinase) — a cellular energy sensor. Effects mirror metformin: reduces hepatic glucose output, improves insulin sensitivity, lowers fasting glucose and HbA1c.
• Dose: 500mg 3×/day with meals (to minimize GI side effects).
• Who benefits most: Individuals with insulin resistance, pre-diabetes, or elevated fasting glucose.
• Caution: Do not combine with insulin or sulfonylureas without physician oversight — additive hypoglycemic effect.

Collagen Peptides (with Vitamin C)

• What it does: Dietary glycine and proline stimulate collagen synthesis in connective tissue — tendons, ligaments, cartilage. Not a muscle-building protein (lacks sufficient leucine). Best used for joint health and injury rehabilitation.
• Dose: 10–15g hydrolyzed collagen + 50mg vitamin C, 30–60 minutes before training or physical therapy sessions.
• Evidence: Modest but growing. Most relevant for connective tissue recovery and injury prevention in athletes with high training loads.

21.4 Herbal Medicine — Botanicals with Scientific Evidence

Traditional herbal medicine systems — Ayurveda, Traditional Chinese Medicine, Western herbalism — offer a rich pharmacological library. This section evaluates key botanicals through the lens of modern clinical research, bridging traditional use with evidence-based application.

Adaptogens: The Stress-Modulating Botanicals

Adaptogens are a pharmacological class of herbs that increase non-specific resistance to physical, chemical, and biological stressors. They modulate the HPA (hypothalamic-pituitary-adrenal) axis and reduce cortisol excess without sedation.

Ashwagandha (Withania somnifera) — ⭐⭐⭐⭐ Strong evidence

Traditional use (Ayurveda): Rasayana (rejuvenating herb); classified as a "Medhya" herb for brain and nerve support.

Active compounds: Withanolides (steroidal lactones) — primary bioactive; also alkaloids and saponins.

Evidence-based benefits:

• Cortisol reduction: 3–27% reduction in serum cortisol in multiple RCTs (Chandrasekhar et al., IJAYP, 2012)
• Strength and muscle: Significant improvements in strength (bench press, leg extension) and muscle recovery in resistance-trained men (Wankhede et al., 2015)
• Testosterone: Modest but significant increase in serum testosterone and LH in men with subclinical hypogonadism
• Thyroid: May upregulate T3 and T4 in subclinical hypothyroid patients (small studies; caution in hyperthyroid conditions)
• Anxiety: Anxiolytic effects comparable to low-dose anxiolytics in some populations
• Sleep: Improved sleep quality and sleep onset latency in adults with insomnia (Langade et al., 2019)

Dose: 300–600mg KSM-66 or Sensoril extract (standardized); 1–2×/day with food. Effects accumulate over 4–8 weeks.

Safety: Generally well-tolerated. Rare: GI discomfort. Contraindicated in: pregnancy, autoimmune thyroid disease (Hashimoto's, Graves'), and before surgery (may potentiate anesthesia).

Rhodiola rosea — ⭐⭐⭐ Moderate-strong evidence

Traditional use: Siberian and Scandinavian traditional medicine for fatigue, endurance, and mental performance under harsh conditions.

Active compounds: Rosavins and salidroside.

Evidence-based benefits:

• Reduces mental and physical fatigue under stress (validated in medical students during exams, night-shift workers, military personnel)
• Improves aerobic endurance (VO₂ max, time to exhaustion) in moderate doses
• Antidepressant activity comparable to sertraline in mild-to-moderate depression (with far fewer side effects) — Mao et al., Phytomedicine, 2015
• Reduces perceived exertion during sustained exercise

Dose: 300–600mg/day standardized extract (3% rosavins, 1% salidroside); taken in the morning (mildly stimulating — may affect sleep if taken after noon).

Safety: Well-tolerated. May cause mild insomnia or vivid dreams if taken late in the day. Avoid in bipolar disorder (activating effect).

Panax Ginseng (Asian Ginseng) — ⭐⭐⭐ Moderate evidence

Traditional use (TCM): Primary "Qi tonic" herb — used for millennia to restore vitality, enhance cognitive function, and support sexual health.

Active compounds: Ginsenosides (triterpenoid saponins).

Evidence-based benefits:

• Improved cognitive performance and working memory in healthy adults
• Erectile dysfunction: modest but statistically significant improvement in multiple RCTs
• Immune function enhancement: reduced incidence and severity of upper respiratory infections
• Blood glucose modulation: modest insulin-sensitizing effect
• Anti-fatigue properties in cancer-related fatigue (higher quality evidence than many applications)

Dose: 200–400mg standardized extract (≥4% ginsenosides)/day. Cycle use: 6–8 weeks on, 2 weeks off.

Safety: Generally safe. Potential interactions with warfarin (blood thinning) and diabetes medications. Avoid high doses in hypertension. Not for children.

Turmeric / Curcumin — ⭐⭐⭐ Moderate evidence

Traditional use (Ayurveda/TCM): Anti-inflammatory, wound healing, digestive support.

Active compound: Curcumin (3–5% of turmeric powder by weight).

Evidence-based benefits:

• Potent anti-inflammatory via NF-κB pathway inhibition — comparable to NSAIDs (ibuprofen) for osteoarthritis pain in several RCTs, with superior GI tolerability
• Antioxidant: upregulates endogenous antioxidant enzymes (SOD, catalase)
• DOMS reduction: 2.5g curcumin/day reduces muscle damage and inflammation markers post-exercise
• Potential anti-cancer, neuroprotective, and antidepressant effects (emerging; mostly preclinical)

Bioavailability problem: Raw curcumin has very poor oral bioavailability (<1%). Solutions:

• Piperine (black pepper, 20mg): Increases curcumin bioavailability by 2,000%
• Phospholipid complex (Meriva): Enhanced absorption form
• Liposomal or micellar preparations: Superior bioavailability

Dose: 500–1,000mg curcumin with piperine, 2–3×/day with fatty meal.

Green Tea Extract (EGCG — Epigallocatechin Gallate) — ⭐⭐⭐ Moderate evidence

Traditional use: Central to Japanese and Chinese health traditions; associated with longevity and cognitive sharpness.

Evidence-based benefits:

• Modest fat oxidation enhancement: meta-analysis shows +80–100 kcal/day additional caloric expenditure (modest, but real)
• LDL-C reduction: 0.2 mmol/L average reduction across meta-analyses
• Neuroprotective: associated with reduced risk of Alzheimer's and Parkinson's in prospective cohort studies
• Cardiovascular protection: endothelial function improvement via nitric oxide production
• Anti-cancer properties: significant in vitro and epidemiological evidence; direct RCT evidence limited

Dose: 400–800mg EGCG/day from standardized extract; or 3–5 cups green tea/day (lower dose, additional L-theanine benefit). Caution: High doses (> 800mg/day EGCG) have been associated with hepatotoxicity in rare cases. Do not exceed recommended doses.

Ginger (Zingiber officinale) — ⭐⭐⭐ Moderate evidence

Traditional use: Universal — digestive aid, anti-nausea, anti-inflammatory across Ayurveda, TCM, and traditional Western herbalism.

Active compounds: Gingerols, shogaols, paradols.

Evidence-based benefits:

• Anti-nausea: strong evidence for pregnancy-related nausea, chemotherapy-induced nausea, and post-operative nausea
• Anti-inflammatory and analgesic: reduces osteoarthritis pain; reduces DOMS by ~25% (Black et al., Journal of Pain, 2010)
• Blood glucose: modest fasting glucose reduction (meta-analysis: −0.58 mmol/L)
• GI motility: accelerates gastric emptying; useful in gastroparesis and nausea from GLP-1 medications

Dose: 1–3g dried ginger/day; 500mg extract 2–3×/day; or fresh ginger in food and teas.

Berberine (Herbal context — Barberry, Goldenseal, Oregon Grape)

Already covered in Section 21.3. Note that berberine is the active compound in multiple traditional herbal preparations used across Ayurveda and TCM for metabolic and antimicrobial purposes — its pharmacological activity was identified and validated from traditional use.

Milk Thistle (Silybum marianum) — Silymarin — ⭐⭐⭐ Moderate evidence

Traditional use: European traditional medicine for liver protection; used since ancient Greece.

Evidence-based benefits:

• Hepatoprotective: protects liver cells from oxidative damage and toxin-induced injury; reduces liver enzymes (ALT, AST) in NAFLD and alcoholic liver disease
• Antifibrotic: may slow progression of liver fibrosis
• Antioxidant: potent free radical scavenger
• Modest blood glucose improvement in T2D (insulin-sensitizing effect)

Dose: 140–420mg silymarin/day (standardized to 70–80% silymarin). Who benefits: NAFLD, elevated liver enzymes from medications, alcohol consumers, those on long-term statin therapy.

Valerian Root (Valeriana officinalis) — ⭐⭐ Moderate evidence (inconsistent)

Traditional use: European and Ayurvedic traditional medicine for sleep and anxiety.

Evidence-based benefits:

• Reduces sleep latency and improves subjective sleep quality (evidence inconsistent across trials; positive signal overall)
• Mild anxiolytic effects via GABA receptor modulation
• May be additive with magnesium glycinate for sleep optimization

Dose: 300–600mg standardized extract, 30–60 minutes before bed. Caution: May cause vivid dreams. Do not combine with benzodiazepines or alcohol. Avoid prolonged use > 4–6 weeks without a break.

Saffron (Crocus sativus) — ⭐⭐ Moderate evidence

Traditional use: Persian traditional medicine for mood, digestion, and as an aphrodisiac.

Evidence-based benefits:

• Antidepressant: multiple RCTs show efficacy comparable to fluoxetine and imipramine in mild-to-moderate depression
• Appetite reduction: 30mg/day saffron extract significantly reduced snacking frequency and appetite in women in one RCT
• PMS symptom reduction
• Eye health: neuroprotective for macular degeneration

Dose: 30mg/day standardized extract.

Fenugreek (Trigonella foenum-graecum) — ⭐⭐ Moderate evidence

Traditional use: Ayurveda, Middle Eastern medicine — for blood sugar, lactation support, and testosterone.

Evidence-based benefits:

• Blood glucose: reduces fasting glucose and postprandial glucose in T2D via galactomannan fiber slowing carbohydrate absorption
• Testosterone: 500mg/day fenugreek extract showed significant improvements in free testosterone and sexual function in men (Steels et al., 2011)
• Appetite reduction and satiety (high soluble fiber content)

Dose: 500–1000mg standardized extract/day or 5–10g ground seeds with meals.

Herbal Safety Principles

21.5 What to Avoid — The Supplement Graveyard

21.6 Evidence-Based Supplement Stacks by Goal

Goal: Fat Loss

Goal: Muscle Building

Goal: Recovery & Sleep

Goal: Metabolic Health / Insulin Sensitivity