Tier 2 — strong

A spermidine-based nutritional supplement prolongs the anagen phase of hair follicles in humans: a randomized, placebo-controlled, double-blind study

Fabio Rinaldi, Barbara Marzani, Daniela Pinto, Yuval Ramot

Dermatology Practical & Conceptual 2017 7(4):17-21

Bibliography

PubMed: PMID 29214104
PubMed Central: PMC5718121
DOI: 10.5826/dpc.0704a05
Funding: Giuliani S.p.A.-linked study
Competing interests: Two authors were Giuliani S.p.A. employees; Fabio Rinaldi served as consultant and Yuval Ramot received travel support.

Study snapshot

Design	Randomized, placebo-controlled, double-blind trial
Model	Healthy adult men and women
Sample	100
Intervention	One spermidine-based nutritional supplement tablet daily versus placebo
Duration	90 days, with pull-test follow-up to 6 months
Endpoints	Anagen V-VI hair follicles; Ki-67; c-Kit; Hair pull test

What the study showed, in plain terms

A 100-person randomized trial reported more anagen-phase hair follicles and favorable follicular markers after a spermidine-based nutritional supplement compared with placebo.

Key findings

The trial supports a signal for hair-cycle biology, but it does not isolate spermidine as the sole active ingredient and is not evidence for longevity or systemic anti-aging outcomes.

What this study can and cannot tell us

Exact supplement composition and spermidine dose were not transparently characterized in the paper. The study was industry-linked: two authors were Giuliani employees, one a consultant and one received travel support.

Editorial review

Reviewed by the Biohack Blueprint research team

Khaled Mahmoud