Frank · The receipts

Where the +15% comes from.

Frank copies its doses, milligram for milligram, from published human studies. Four of those studies measured testosterone. This page shows their results, the average we quote, and exactly how we calculated it — so you can check our math.

The four studies

Ingredient (Frank's dose)	Study	Who · how long	Testosterone result	Change	Vs placebo
Tongkat Ali — Physta® 200 mg	Chinnappan 2021, Food Nutr Res	105 men, 50–70, RCT · 12 weeks	Serum total T: 200.5 → 225.0 ng/dL (200 mg group, p<0.001 vs placebo)	+12.2%	+15.0%
Shilajit — PrimaVie® 500 mg	Pandit 2016, Andrologia	Healthy men, 45–55, RCT · 90 days	Serum total T up significantly vs placebo (free T +19.1%, DHEAS +31.4%)	+20.5%	+20.5%
Ashwagandha — Shoden® (21 mg withanolide glycosides)	Lopresti 2019, Am J Mens Health	57 men, 40–70, RCT crossover · 8 weeks	Salivary T: 310.0 → 355.6 pmol/L (p=.010)	+14.7%	+14.7%
Fenugreek — Testofen® 600 mg	Rao 2016, The Aging Male	120 men, 43–70, RCT · 12 weeks	Serum total T: 12.3 → 13.8 nmol/L (p=0.001 vs placebo); free T 241 → 264 pmol/L	+12.2%	+18.3%

The math

We take each study’s primary testosterone outcome, compute the percent change in the supplement group, and average the four numbers. No weighting, no cherry-picking, no dropping the smallest result.

(+12.2% + 20.5% + 14.7% + 12.2%) ÷ 4 = +14.9%

Rounded: ≈ +15% on average over 8–12 weeks.

If we instead adjust each result against its placebo group (placebo drifted down in two studies), the same math gives +17.1%. We quote the lower number.

(+15.0% + 20.5% + 14.7% + 18.3%) ÷ 4 = +17.1%

What this number is not

It is not a study of Frank. Each result comes from one ingredient tested on its own. Frank uses the same branded extracts at the same daily doses, but the combined formula has not been through its own trial. Effects from different ingredients don’t simply add up — which is one reason we quote an average, never a sum.
The studies measured different things. Three measured blood testosterone, one measured saliva. Populations, baselines and labs differ. Averaging across them is an honest summary, not a precise prediction.
Your result will vary. The men in these studies were 40–70, mostly with low-normal testosterone. That’s who Frank is built for. If your levels are already high, expect less.
Timeframe. All four studies completed within 90 days — two ran 12 weeks, one 8 weeks, and the shilajit study a full 90 days. That’s what “within 90 days” means on our homepage, and it’s why Frank’s guarantee gives you the same window.

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*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Sources: PubMed 34262417, 26395129, 30854916, 26791805. Percent changes computed from published group means; placebo-adjusted figures subtract the placebo group’s percent change over the same period.