Hair thinning and loss

A 2019 meta-analysis of RCTs found low-level laser and light therapy significantly increased hair density versus sham (standardized mean difference 1.32), and a 2021 meta-analysis of FDA-cleared home devices supported efficacy across comb and helmet designs in both sexes. Caveats are real: many trials were manufacturer-funded, and effects need continuous use of 3 or more sessions weekly to maintain. It is a legitimate adjunct to minoxidil or finasteride for pattern hair loss.

A 2023 systematic review and meta-analysis of RCTs found PRP significantly increased hair density versus placebo at 3 and 6 months, and a 2024 meta-analysis of randomized trials estimated a mean gain of 27.6 hairs per square centimeter (95 percent CI 14.0 to 41.1). Typical protocols use 3 monthly injections plus periodic boosters. Limitations are honest ones: high heterogeneity between studies, unstandardized PRP preparations, and evidence of publication bias, so the grade stops at moderate.

PRF for androgenetic alopecia borrows plausibility from its cousin PRP, which has meta-analysis-level evidence of increased hair density at 3 and 6 months. PRF-specific data is much smaller: a 2024 review found early case series and small trials suggesting improved hair growth but concluded controlled trials are needed before PRF can be considered proven for hair loss. If choosing between them today, PRP has the stronger evidence base.

A 2023 systematic review of exosomes for hair restoration found 16 studies, of which 15 were preclinical (cells and animals) and only 1 was in humans: a report of 39 androgenetic alopecia patients showing increased hair density and thickness with topical adipose stem cell exosomes, without a control group. Animal biology is promising, but one uncontrolled human study is not evidence a paid treatment works. Established options like minoxidil, finasteride, and PRP all have far more human data.