Every nutraceutical brand uses some combination of these tactics to make their evidence look stronger than it is. Here's what to watch for on this product specifically.
⚑ Primary endpoint not reported
The flagship 2025 men's RCT didn't report its primary endpoint
Nutrafol's 2025 men's trial (NCT05339958) registered an objective primary endpoint on the US clinical trials registry: terminal hair counts via Canfield HairMetrix phototrichogram at Day 180. The paper did not report this primary endpoint. It states verbatim: "numerous protocol deviations specifically related to the Canfield HairMetrix occurred at one site, rendering many phototrichograms unusable... only secondary end points are presented here." The endpoint shift was never amended on the registry before publication. The abstract does not disclose the failure. What gets quoted in marketing is the secondary endpoint — investigator global ratings and a patient questionnaire. Not the hair count. Not the Canfield photos. It is highly unusual for a hair loss trial not to report hair counts.
⚑ All authors brand-affiliated
Every author of every published Nutrafol trial is brand-affiliated
Across the 2018, 2021, 2022, and 2025 Nutrafol RCTs, every author has had a financial relationship with the manufacturer — direct employees of Nutraceutical Wellness Inc., paid advisors, or grant recipients. The 2018 foundational study (n=40 women) listed Nutrafol's own Co-founder and Chief Medical Advisor as second author. There is no independent product-level replication anywhere in the published literature.
⚑ Sponsored
100% manufacturer-funded
Every published trial of Nutrafol was funded by Nutraceutical Wellness Inc. There is zero independent replication.
⚑ No active comparator
Never tested against minoxidil or finasteride
No trial has compared Nutrafol head-to-head with an FDA-approved hair loss treatment. We don't know whether Nutrafol works as well, less well, or about the same — only that the secondary endpoints beat placebo in sponsored studies.
⚑ Mega-dose biotin
Biotin at 10,000% DV with documented lab-interference risk
3,000 mcg per serving. Far above the FDA's 150 mcg labeling threshold for required lab-interference disclosure. Documented to distort troponin, TSH, and hCG immunoassays. The FDA has cited at least one death potentially linked to a falsely low troponin reading in a biotin user.
⚑ Mega-dose selenium
Selenium at half the toxicity ceiling — before counting food
200 mcg per serving sits at 50% of the adult tolerable upper intake level (400 mcg). One Brazil nut runs ~68–91 mcg; a 3 oz tuna serving ~92 mcg. A normal day of dietary intake stacked on top of the supplement can put a user at the upper limit. Selenosis — chronic selenium toxicity — has hair loss as a hallmark sign. A strange dose to choose for a hair-loss product.
⚑ Selection bias
Inclusion criteria favor responders
Trials enrolled women with 'self-perceived thinning hair' — a population already motivated to perceive improvement. Strict androgenetic alopecia diagnostic criteria were not consistently applied.
⚑ Proprietary blend
Sub-ingredient doses are hidden inside two proprietary blends
The 'Synevia Hair Growth Complex' and Nutrafol's other proprietary blend hide individual active doses. You can't verify whether the saw palmetto dose hits any clinically studied amount — and at any standalone dose tested in non-industry trials (Strauch 1994, Pytel 2002), saw palmetto did not move serum DHT.
⚑ Regulatory action
Truth In Advertising filed an FTC/FDA complaint in 2023
In April 2023, the consumer advocacy group Truth in Advertising filed a formal FTC/FDA complaint alleging deceptive 'clinically proven' claims and ROSCA subscription violations. Multiple consumer class actions followed in the S.D.N.Y.
⚑ Active litigation
A consolidated class action has been pending for 2+ years
The Smith v. Nutraceutical Wellness case (S.D.N.Y., 2023) was dismissed after a settlement. The consolidated case Nutraceutical Wellness, Inc. Consumer Fraud Litigation (five named plaintiffs) is pending before Judge Gardephe. The motion to dismiss has been fully briefed since March 2024 and remains undecided over two years later. The Smith complaint alleged Nutrafol's foundational trial is 'so flawed in its basic construction and design' that it cannot establish causal benefit — a critique that carried forward into the consolidated litigation.
⚑ Short duration
No long-term data
All trials run 6 months. We don't know if benefits persist past one year — or whether years of supplementation cause any harm.