Nutrafol study redefines hair growth efficacy metrics, impacts supplement claims

London, United Kingdom — 28 July 2026

A recent study published in Dermatology and Therapy introduces linear hair growth rate (LHGR) as an objective, quantifiable metric for assessing hair growth supplement efficacy. Funded by Nutraceutical Wellness, parent company of Nutrafol, the research highlights that LHGR measures the speed of individual hair growth, a distinction from traditional metrics like hair density or shedding counts. This development offers supplement manufacturers a new dimension for product validation and potential marketing claims.

The study, which tracked 180 women aged 18 to 70 with hair thinning, found average hair growth rates increased by 18.6% to 36.7% from baseline measurements across four Nutrafol formulations over six months. Researchers also observed increased active growth (anagen) phase hairs and improved scalp coverage, with total hair counts rising 4.4% to 8.2% and terminal hair counts by 6% to 7.9%. Dr. Isabelle Raymond, Senior Vice President of Global Clinical and Medical Affairs at Nutrafol, stated, "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."

While the study relied on a baseline comparison rather than a placebo-controlled design—a limitation acknowledged by researchers—it underscores the potential for more nuanced efficacy claims. Measuring LHGR is technically demanding, requiring precise methodology like the Canfield HairMetrix imaging system used in the study. Manufacturers seeking to adopt this metric will need to invest in advanced analytical capabilities or collaborate with specialised contract research organisations.

What this means for United Kingdom

UK brand owners must assess how LHGR claims can enhance product differentiation in a competitive hair health market, potentially attracting new consumer segments seeking faster results. This may necessitate reformulation windows and investment in clinical trials using LHGR as a primary endpoint, with costs ranging from £50,000 to £200,000 for a robust six-month study. Regulatory teams should monitor guidance from the FSA and ASA regarding substantiation for novel growth rate claims, anticipating potential compliance deadlines in early 2027. Procurement leads must negotiate with ingredient suppliers for compounds backed by early growth rate data, securing favourable MOQs and lead times to support new product development cycles.

The findings suggest a shift in evidence requirements for hair growth products, moving beyond simple hair count increases to more dynamic growth assessments. This evolution demands that formulation chemists understand ingredient bioefficacy at the cellular level to influence anagen phase duration and linear extension. Brands that can robustly demonstrate improvements in LHGR will gain a significant competitive advantage, especially as consumers become more discerning about product efficacy and scientific backing. This opens opportunities for premiumisation and market share gains for agile manufacturers.

Brand owners increasingly rely on contract-manufacturing partners such as Supplement Factory to navigate these requirements.