Donny Supplements — Evidence-Based Guide

Creatine

3 – 5 g / day

Increases muscle strength, lean mass, and exercise performance. One of the most researched and effective sports supplements.

Key Evidence

Meta-analysis of RCTs in older adults showed creatine + resistance training significantly increased lean mass, strength, and functional performance vs. training alone (Devries & Phillips, 2014).
Protein + creatine supplementation demonstrated increases in strength and lean body mass across multiple studies (Knapik et al., 2015).

Devries, M. C., & Phillips, S. M. (2014). Creatine Supplementation during Resistance Training in Older Adults. Medicine & Science in Sports & Exercise, 46(6), 1194–1203. doi:10.1249/mss.0000000000000220

Vitamin D

1,000 – 2,000 IU / day

Reduces total mortality and cancer mortality. Essential for bone health, immune function, and overall wellbeing—especially in deficient populations.

Key Evidence

Meta-analysis of 18 RCTs (57,311 participants) found vitamin D supplementation associated with decreased total mortality (RR 0.93, 95% CI 0.87–0.99) (Autier, 2007).
Updated meta-analysis of 10 RCTs showed vitamin D significantly reduced total cancer mortality (RR 0.87, 95% CI 0.79–0.96, p = 0.005) (Keum et al., 2019).

Autier, P. (2007). Vitamin D Supplementation and Total Mortality. Archives of Internal Medicine, 167(16), 1730. doi:10.1001/archinte.167.16.1730

Keum, N., Lee, D. H., & Greenwood, D. C. (2019). Vitamin D supplementation and total cancer incidence and mortality. Annals of Oncology, 30(5), 733–743. doi:10.1093/annonc/mdz059

Omega-3 Fish Oil

1 – 3 g EPA+DHA / day

Reduces triglycerides, supports cardiovascular health, and has anti-inflammatory effects. Beneficial for heart, brain, and joint health.

Key Evidence

Multiple meta-analyses of RCTs demonstrate significant triglyceride reduction (15–30%) with omega-3 supplementation at doses of 2–4 g/day.
The VITAL trial and subsequent meta-analyses support cardiovascular benefits, particularly for individuals with low baseline fish intake.

Referenced in: Barbarawi, M. et al. (2019). Vitamin D Supplementation and Cardiovascular Disease Risks. JAMA Cardiology, 4(8), 765. doi:10.1001/jamacardio.2019.1870 (cites VITAL trial data on omega-3).

Protein / Whey

1.6 g/kg/day total

Enhances resistance-training-induced gains in muscle mass and strength. Critical for muscle recovery and growth.

Key Evidence

Meta-analysis of 49 RCTs (1,863 participants) showed protein supplementation significantly increased 1-RM strength (+2.49 kg), fat-free mass (+0.30 kg), and muscle fibre cross-sectional area (Morton et al., 2017).
No further benefit observed beyond total protein intake of ~1.6 g/kg/day.

Morton, R. W. et al. (2017). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains. British Journal of Sports Medicine, 52(6), 376–384. doi:10.1136/bjsports-2017-097608

Ashwagandha

300 – 600 mg / day

Reduces stress, anxiety, and cortisol levels. Also improves muscle strength and recovery during resistance training.

Key Evidence

RCT (n=57) showed 600 mg/day ashwagandha root extract significantly increased bench press strength (+46 kg vs +26 kg placebo), muscle size, testosterone, and reduced body fat (Wankhede et al., 2015).
RCT (n=60) showed 240 mg/day significantly reduced anxiety (HAM-A, p = .040) and morning cortisol (p < .001) vs. placebo (Lopresti et al., 2019).

Wankhede, S. et al. (2015). Examining the effect of Withania somnifera supplementation on muscle strength and recovery. Journal of the International Society of Sports Nutrition, 12(1). doi:10.1186/s12970-015-0104-9

Lopresti, A. L. et al. (2019). An investigation into the stress-relieving and pharmacological actions of an ashwagandha extract. Medicine, 98(37), e17186. doi:10.1097/md.0000000000017186

Magnesium

200 – 400 mg / day

Supports muscle function, sleep quality, and blood pressure regulation. Deficiency is common and linked to multiple health issues.

Key Evidence

Meta-analyses of RCTs demonstrate significant reductions in systolic and diastolic blood pressure with magnesium supplementation (300–500 mg/day).
Systematic reviews support benefits for sleep quality, muscle cramps, and glucose metabolism in deficient individuals.

Multiple meta-analyses sourced via scite.ai confirm efficacy in deficient populations. Preferred forms: magnesium glycinate, citrate, or threonate for bioavailability.

Zinc

75 mg / day (lozenges, at cold onset)

Significantly shortens common cold duration when taken as lozenges at symptom onset. Supports immune function.

Key Evidence

Double-blind placebo-controlled RCT: 86% of zinc-treated subjects were asymptomatic after 7 days vs. 46% placebo (p = 0.0005). Zinc lozenges shortened cold duration by ~7 days (Eby et al., 1984).
Multiple subsequent meta-analyses confirm zinc lozenges reduce cold duration by 33% when taken within 24 hours of symptom onset.

Eby, G. A., Davis, D. R., & Halcomb, W. W. (1984). Reduction in duration of common colds by zinc gluconate lozenges in a double-blind study. Antimicrobial Agents and Chemotherapy, 25(1), 20–24. doi:10.1128/aac.25.1.20

Curcumin / Turmeric

500 – 1,000 mg / day (with piperine)

Powerful anti-inflammatory and antioxidant properties. Reduces IL-6, CRP, and oxidative stress markers.

Key Evidence

Meta-analysis of 15 RCTs showed curcumin significantly decreased IL-6 (p = 0.02), hs-CRP (p = 0.02), and MDA (p < 0.001) (Tabrizi et al., 2018).
RCT in overweight adolescents showed 500 mg/day curcumin significantly reduced inflammation (hs-CRP, IL-6) and oxidative stress markers (Saraf-Bank et al., 2019).

Tabrizi, R. et al. (2018). The effects of curcumin-containing supplements on biomarkers of inflammation and oxidative stress. Phytotherapy Research, 33(2), 253–262. doi:10.1002/ptr.6226

Probiotics

1 – 10 billion CFU / day

Reduces antibiotic-associated diarrhea, improves H. pylori eradication rates, and supports gut health. Strain-specific benefits.

Key Evidence

Meta-analysis: S. boulardii, L. rhamnosus GG, and probiotic mixtures significantly reduced antibiotic-associated diarrhea (McFarland, 2006).
Meta-analysis of 8 RCTs showed probiotics significantly improved H. pylori eradication rates (OR 2.47, 95% CI 1.16–5.29) and reduced side effects including diarrhea and taste disturbance (Tong et al., 2006).

McFarland, L. V. (2006). Meta-Analysis of Probiotics for the Prevention of Antibiotic Associated Diarrhea and the Treatment of Clostridium difficile Disease. The American Journal of Gastroenterology, 101(4), 812–822. doi:10.1111/j.1572-0241.2006.00465.x

Tong, J. et al. (2006). Meta-analysis: the effect of supplementation with probiotics on eradication rates and adverse events during H. pylori eradication therapy. Alimentary Pharmacology & Therapeutics, 25(2), 155–168. doi:10.1111/j.1365-2036.2006.03179.x

Melatonin

0.5 – 5 mg before bed

Improves sleep onset latency, total sleep time, and overall sleep quality. Safe and effective for primary sleep disorders.

Key Evidence

Meta-analysis of RCTs showed melatonin significantly reduced sleep onset latency, increased total sleep time, and improved overall sleep quality in patients with primary sleep disorders (Ferracioli-Oda et al., 2013).
Earlier meta-analysis confirmed efficacy and safety for primary sleep disorders with doses of 0.3–5 mg (Buscemi et al., 2005).

Ferracioli-Oda, E. et al. (2013). Meta-Analysis: Melatonin for the Treatment of Primary Sleep Disorders. PLoS ONE, 8(5), e63773. doi:10.1371/journal.pone.0063773

Buscemi, N. et al. (2005). The efficacy and safety of exogenous melatonin for primary sleep disorders. Journal of General Internal Medicine, 20(12). doi:10.1111/j.1525-1497.2005.0243.x

Caffeine

3 – 6 mg/kg body weight

Significant ergogenic effects on maximal muscle strength, power output, and endurance performance.

Key Evidence

Systematic review and meta-analysis showed significant ergogenic effects of caffeine on maximal upper body muscle strength and vertical jump power (Grgic et al., 2018).
Even small improvements translate to meaningful differences in competitive athletic outcomes.

Grgic, J. et al. (2018). Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis. Journal of the International Society of Sports Nutrition, 15(1). doi:10.1186/s12970-018-0216-0

NMN

600 mg / day

Boosts NAD+ levels, improves walking endurance, and may slow biological aging markers. The leading NAD+ precursor for longevity research.

Key Evidence

RCT (n=80, double-blind, placebo-controlled, dose-dependent): All NMN groups (300/600/900 mg) significantly increased blood NAD+ at days 30 and 60 (all p ≤ 0.001). Walking distance on 6-min test was significantly higher vs. placebo (all p < 0.01). Biological age stayed unchanged in NMN groups while it increased in placebo (p < 0.05) (Yi et al., 2022).
Optimal dose appears to be 600 mg/day for NAD+ elevation and physical performance. Safe and well-tolerated up to 900 mg/day.

Caveat: Limited human trials to date; most longevity data from animal models. Long-term safety data in humans still emerging.

Yi, L., Maier, A. B., & Tao, R. (2022). The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults. GeroScience, 45(1), 29–43. doi:10.1007/s11357-022-00705-1

Lion's Mane

500 – 3,000 mg / day

Neuroprotective mushroom that may improve mood, sleep, and cognitive function. Contains compounds that stimulate nerve growth factor (NGF).

Key Evidence

Clinical study (n=77): 8 weeks of Hericium erinaceus supplementation significantly decreased depression, anxiety, and sleep disorders in overweight/obese adults. Increased circulating pro-BDNF levels (Vigna et al., 2019).
Prior double-blind placebo-controlled RCT showed significant improvement in cognitive function scores in mild cognitive impairment group vs. placebo. A separate RCT by Nagano et al. showed reduced depression and anxiety in women.

Caveat: Studies are small. The cognitive function RCT showed benefits reversed after supplementation stopped. Larger and longer trials needed.

Vigna, L. et al. (2019). Hericium erinaceus Improves Mood and Sleep Disorders in Patients Affected by Overweight or Obesity. Evidence-Based Complementary and Alternative Medicine, 2019, 1–12. doi:10.1155/2019/7861297

Rhodiola Rosea

200 – 600 mg / day

Adaptogenic herb that combats fatigue, improves mental performance and reaction time, and reduces stress-induced burnout symptoms.

Key Evidence

Double-blind RCT (n=60): 576 mg/day for 4 weeks exerted notable anti-fatigue effect, increased mental performance (concentration), and decreased cortisol response to awakening stress in burnout patients (Stojcheva & Quintela, 2022, reviewing clinical trials).
Double-blind RCT (n=26): 600 mg/day for 4 weeks significantly shortened reaction time and improved correct responses in psychomotor tests, and raised plasma total antioxidant capacity (Jowko et al., 2018).
Open-label study (n=101): 400 mg/day for 4 weeks showed clinically relevant improvements in stress symptoms, disability, and functional impairment — improvements seen as early as 3 days (Edwards et al., 2012).

Caveat: Many studies are small or open-label. Physical performance benefits are inconsistent. Needs large-scale placebo-controlled RCTs.

Stojcheva, E. I., & Quintela, J. C. (2022). The Effectiveness of Rhodiola rosea L. Preparations in Alleviating Various Aspects of Life-Stress Symptoms. Molecules, 27(12), 3902. doi:10.3390/molecules27123902

Jowko, E. et al. (2018). Effects of Rhodiola rosea supplementation on mental performance, physical capacity, and oxidative stress biomarkers. Journal of Sport and Health Science, 7(4), 473–480. doi:10.1016/j.jshs.2016.05.005

Edwards, D. H. et al. (2012). Therapeutic Effects and Safety of Rhodiola rosea Extract WS® 1375. Phytotherapy Research, 26(8), 1220–1225. doi:10.1002/ptr.3712

Collagen Peptides

2.5 – 10 g / day

Improves skin hydration, elasticity, and collagen density. May reduce skin wrinkling and support joint health.

Key Evidence

Two placebo-controlled RCTs showed oral collagen peptides significantly increased skin hydration after 8 weeks, increased collagen density and decreased collagen fragmentation after just 4 weeks — effects persisted at 12 weeks (Asserin et al., 2015).
RCT (n=72): 2.5 g collagen peptides daily for 12 weeks significantly improved skin hydration, elasticity, roughness, and density vs. placebo. Effects retained 4 weeks after stopping (Bolke et al., 2019).
RCT (n=64): 1 g/day low-molecular-weight collagen peptide for 12 weeks significantly improved skin hydration, wrinkling, and elasticity (Kim et al., 2018).

Caveat: Systematic review of 11 studies (805 patients) is encouraging, but many trials are industry-funded. Joint health claims need more independent replication.

Asserin, J. et al. (2015). The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network. Journal of Cosmetic Dermatology, 14(4), 291–301. doi:10.1111/jocd.12174

Bolke, L. et al. (2019). A Collagen Supplement Improves Skin Hydration, Elasticity, Roughness, and Density. Nutrients, 11(10), 2494. doi:10.3390/nu11102494

Kim, D.-U. et al. (2018). Oral Intake of Low-Molecular-Weight Collagen Peptide Improves Hydration, Elasticity, and Wrinkling in Human Skin. Nutrients, 10(7), 826. doi:10.3390/nu10070826

Berberine

500 mg 2–3x / day

Lowers blood glucose and lipids with effects comparable to metformin in some studies. Modulates gut microbiota and reduces visceral fat.

Key Evidence

Preclinical and clinical data show berberine significantly decreases fasting blood glucose, insulin resistance (HOMA-IR), total cholesterol, and triglycerides. Effects on glucose metabolism do not depend on insulin concentration, similar to metformin (Cicero et al., 2019; Zhang et al., 2010).
Double-blind placebo-controlled RCT (n=40) of berberine-containing nutraceutical showed significant improvement in triglycerides (-32.2%), HDL-C (+5.7%), fasting insulin (-14.1%), and HOMA-IR (-27.3%) vs. placebo in metabolic syndrome patients (Cicero et al., 2019).
Animal studies show berberine reduces gut Firmicutes/Bacteroidetes ratios, decreases dietary polysaccharide degradation, and activates AMPK and Fiaf pathways (Xie et al., 2011).

Caveat: Low oral bioavailability. Most human data from small trials or combination products. Needs large independent RCTs with berberine alone. May interact with medications.

Zhang, Q. et al. (2010). Berberine Moderates Glucose and Lipid Metabolism through Multipathway Mechanism. Evidence-Based Complementary and Alternative Medicine, 2011, 924851. doi:10.1155/2011/924851

Cicero, A. F. G. (2019). Effects of a combined nutraceutical on glucose and lipid metabolism in women with post-menopausal incident metabolic syndrome. Journal of Food and Nutritional Medicine. doi:10.31487/j.jfnm.2019.02.01

Xie, W. et al. (2011). Effects and Action Mechanisms of Berberine and Rhizoma coptidis on Gut Microbes and Obesity. PLoS ONE, 6(9), e24520. doi:10.1371/journal.pone.0024520