In-clinic hair loss treatments and their evidence

Sources: PRP^[1], dutasteride mesotherapy^[2], laser comb^[3] and the Japanese guideline^[4].

PRP starts with a blood sample taken like a routine blood test. A centrifuge separates the platelet-rich part, which carries growth factors, and the doctor injects it into the thinning areas of the scalp in a grid of small injections. Kits and preparation methods differ between clinics and studies, which is one reason results vary.

A 2023 systematic review pooled nine randomised trials with 238 patients. PRP increased hair density at three and six months compared with placebo. Hair count and hair diameter rose from baseline but were not significantly different from placebo, and no serious adverse reactions were reported^[1]. In women, a 2023 meta-analysis of seven studies found higher terminal hair density with PRP than with control treatments, with no significant difference in hair thickness and no major side effects^[5].

In practice PRP is given as a course of several sessions a few weeks apart, followed by a review of photos. If it helps, maintenance sessions are spaced further apart.

Mesotherapy delivers a medicine into the skin of the scalp through many tiny injections. Dutasteride scalp injections have been studied for pattern hair loss, but the evidence is limited and does not show that injections are safer than tablets. A 2025 systematic review found consistent improvements in hair density and thickness with mild local irritation and no significant systemic effects, but called the evidence limited by small, varied studies^[2].

A wider 2026 review of scalp injection therapies reached a similar view: possible cosmetic benefit, particularly with dutasteride, but not yet enough evidence for routine use. It also recorded rare but real problems, including paradoxical hair loss, scarring and acute dermatitis^[6]. Ask what exactly is injected, how often and by whom.

The laser comb tested in these trials, the HairMax Lasercomb, is FDA-cleared through the 510(k) pathway; its first clearance dates from January 2007 (FDA 510(k) record K060305, checked 2026-10-18). In a set of randomised, sham-controlled trials, the comb used three times a week for 26 weeks increased terminal hair density by about 18 to 26 hairs per cm², compared with about 2 to 9 with the sham device, in both men and women. No serious adverse events were reported^[3]. The 2017 Japanese guideline recommends light-emitting diodes and low-level lasers for male pattern hair loss^[4]. Because these devices are mainly for home use, they suit a visitor who wants something to continue after the trip.

Exosomes are tiny vesicles released by cells, and exosome and stem-cell-derived products are marketed for hair loss in Korea and elsewhere. A 2026 systematic review found that early clinical studies reported hair density gains of 8 to 20%, but they were small, often retrospective and frequently had no control group; manufacturing standards and regulation are still unsettled^[7].

In the United States, the FDA’s consumer alert on regenerative medicine products states that there are no approved exosome products (FDA consumer alert, page current as of 2024-04-09, checked 2026-10-18). If any clinic offers an exosome or stem-cell product for hair, ask what the product is, how it is registered in Korea and which controlled trial supports it for hair.

Guidelines for pattern hair loss put medicines first, because their evidence is larger and longer^[8][4]. In-clinic treatments can be used alongside medicines, or instead of them when a medicine is unsuitable or has not helped enough. Other types of hair loss follow different rules: alopecia areata, for example, is treated with corticosteroids or JAK inhibitors under its own guideline^[9].

1. Photos and a brief check of the scalp.
2. A blood sample, then a short wait while the PRP is prepared.
3. Numbing or cooling, if the clinic uses it, then the scalp injections.
4. Aftercare advice: clinics commonly ask you to skip saunas, hard exercise and alcohol that day and to wash your hair from the next day.

Tenderness, a feeling of tightness and small marks usually settle within a few days. Tell the doctor if you take blood thinners or have a bleeding or platelet disorder, because these change whether PRP is suitable.