The Effect of Platelet-Rich Plasma in Hair Regrowth: A Randomized Placebo-Controlled Trial


Platelet-rich plasma (PRP) has emerged as a new treatment modality in
regenerative plastic surgery, and preliminary evidence suggests that it
might have a beneficial role in hair regrowth. Here, we report the
results of a randomized, evaluator-blinded, placebo-controlled,
half-head group study to compare, with the aid of computerized
trichograms, hair regrowth with PRP versus placebo. The safety and
clinical efficacy of autologous PRP injections for pattern hair loss
were investigated. PRP, prepared from a small volume of blood, was
injected on half of the selected patients' scalps with pattern hair
loss. The other half was treated with placebo. Three treatments were
administered to each patient at 30-day intervals. The endpoints were
hair regrowth, hair dystrophy as measured by dermoscopy, burning or
itching sensation, and cell proliferation as measured by Ki67
evaluation. Patients were followed for 2 years. Of the 23 patients
enrolled, 3 were excluded. At the end of the 3 treatment cycles, the
patients presented clinical improvement in the mean number of hairs,
with a mean increase of 33.6 hairs in the target area, and a mean
increase in total hair density of 45.9 hairs per cm2 compared
with baseline values. No side effects were noted during treatment.
Microscopic evaluation showed the increase of epidermis thickness and of
the number of hair follicles 2 weeks after the last PRP treatment
compared with baseline value (p < .05). We also observed an increase of Ki67+
keratinocytes in the epidermis and of hair follicular bulge cells, and a
slight increase of small blood vessels around hair follicles in the
treated skin compared with baseline (p < .05). Relapse of
androgenic alopecia was not evaluated in all patients until 12 months
after the last treatment. After 12 months, 4 patients reported
progressive hair loss; this was more evident 16 months after the last
treatment. Those four patients were re-treated. Our data clearly
highlight the positive effects of PRP injections on male pattern hair
loss and absence of major side effects. PRP may serve as a safe and
effective treatment option against hair loss; more extensive controlled
studies are needed.

Article by
Bryn Mawr Physician