Women taking targeted hair supplements experienced faster hair growth and improvements in hair count and scalp coverage over six months, according to a study published this month in Dermatology and Therapy.
Nutraceutical Wellness, Nutrafol’s parent company, funded the study and publication fees. Two authors are company employees, one previously worked for the company, and Dr. Raja K. Sivamani received research funding from Nutraceutical Wellness and served as a scientific adviser.
The researchers focused on linear hair growth rate, or LHGR, which measures how much individual hairs grow over a set period. Unlike hair density, which shows how many hairs are present, LHGR indicates how quickly those hairs are growing.
Across four Nutrafol formulations, average hair growth rates increased by between 18.6% and 36.7% from participants’ baseline measurements. The researchers also recorded more hairs in the active growth stage, higher terminal hair counts and improved scalp coverage.
Measuring how fast hair grows
Speaking to NutraIngredients, Dr. Isabelle Raymond, senior vice president of global clinical and medical affairs at Nutrafol, said growth rate offers manufacturers and clinicians information that cannot be captured through hair counts alone.
“Linear hair growth rate is a clinically meaningful endpoint because it gives researchers and clinicians an objective, quantifiable measure that isolates growth from other hair measures such as density and shedding,” Raymond said.
“It has been infrequently evaluated because it is technically demanding to measure,” she added.
As detailed in the study, at each assessment, researchers clipped hair in a small, marked area of the scalp. Participants returned 48 hours later, when the team used the Canfield HairMetrix imaging system to measure how much the hairs had grown.
The study enrolled 180 women aged 18 to 70 with hair thinning confirmed by a dermatologist. A total of 150 completed the study according to the protocol.
Participants received one of four supplements designed for different groups, including younger women, women following plant-based diets and women going through menopause. The postpartum product was tested in women who were not postpartum because the researchers wanted a more stable starting point for measuring changes.
More hairs remained in growth phase
The researchers reported significant increases in hair growth rate after 90 days, with the improvements maintained or increased at 180 days.
They also measured changes in the hair growth cycle. Hair normally moves through an active growth stage, known as anagen, followed by resting and shedding stages.
All four groups had more hairs in the anagen stage after six months. As reported in the study, total hair counts increased by between 4.4% and 8.2%, while terminal hair counts, meaning thicker, more visible hairs, increased by between 6% and 7.9%. Scalp coverage rose by between 5.3% and 8.5%.
“Growth rate, active growth phase, terminal hair counts and coverage each answer a different question...together they provide a more clinically meaningful view of change,” Raymond said.
She added that the findings suggest the products affected several aspects of hair growth at the same time, rather than simply increasing the number of hairs counted in one area.
Study design limits conclusions
The study did not include a placebo group, and participants knew which products they were taking. This means the research cannot rule out natural changes in hair growth over time or other factors that may have influenced the results.
Researchers instead compared each participant’s results with her own baseline. Raymond said this approach helped account for the wide differences in hair growth rates between individuals, but acknowledged that it did not replace a controlled trial.
“We see this publication as an important addition to that evidence base, particularly because it evaluates a technically challenging endpoint that has rarely been studied, not as a substitute for controlled research,” she said.
Source: Dermatology and Therapy (2026) doi: 10.1007/s13555-026-01866-z “A 6-Month Prospective, Open-Label, Randomized Study Showing Increased Hair Growth Rate in Women Using Multi-Targeting Hair Growth Nutraceuticals.” Authors: Rubaina Dang et al.
