HBOT vs PRP: which has stronger evidence

Why do patients compare HBOT and PRP as hair transplant adjuncts?

PRP and HBOT are the two adjuncts clinics most often bundle into hair transplant packages, marketed with similar promises of better graft survival, faster healing and stronger growth. A fair comparison separates two questions: does each treatment have any evidence base, and does that evidence actually concern what it is being sold for?

How much research evidence exists for PRP compared with HBOT?

PRP has a substantial evidence base, including Kieling's 2024 systematic review and Xiao's 2024 meta-analysis of six studies (343 participants) showing greater density gains combined with Minoxidil. HBOT's entire hair-specific literature is one 34-patient trial, a five-patient case report, a nine-volunteer pilot study, and a letter to the editor — far less by volume.

PRP

Platelet-rich plasma for androgenetic alopecia has been studied extensively enough to support multiple systematic reviews and meta-analyses. Kieling and colleagues published a systematic review and meta-analysis in Anais Brasileiros de Dermatologia in 2024 examining whether autologous PRP increases hair density in androgenetic alopecia. Xiao and colleagues published a meta-analysis of PRP combined with Minoxidil in Aesthetic Plastic Surgery the same year, pooling six studies and 343 participants and reporting greater increases in hair density and diameter with combination therapy than with either treatment alone.

The PRP literature has well-documented problems — small studies, heterogeneous preparation protocols, variable platelet concentrations, inconsistent outcome measures — but there is a genuine body of randomised evidence to argue about.

HBOT

The hair-specific literature on hyperbaric oxygen is one randomised trial of 34 patients (Fan and colleagues, 2021), a five-patient case report (Giardiello and colleagues, 2025), a preliminary study in nine healthy volunteers (Lee and colleagues, 2026), and a letter to the editor.

On volume, this is not close. PRP has a research literature; HBOT has a handful of papers.

Does PRP's larger evidence base mean it's proven to help graft survival?

No. Almost all PRP evidence concerns treating a thinning scalp for androgenetic alopecia, not injecting PRP at surgery to protect grafts — a different question studied much less. HBOT's single small trial was conducted in transplant patients but found a null result on nine-month survival, with benefit shown only in early shedding and inflammation.

Almost all of the PRP evidence concerns injecting PRP into a thinning scalp to treat androgenetic alopecia over months. That is a different intervention from injecting PRP at the time of surgery to improve the survival of transplanted grafts.

The post-transplant graft-survival question has been studied much less for PRP than the AGA question has, and the same caveat that applies to HBOT applies here: an evidence base for a related indication is not evidence for this one.

Meanwhile the one thing HBOT does have is a randomised trial conducted specifically in hair transplant patients, with a hair transplant outcome. It is small, and its result on nine-month survival was null. But it is on-topic in a way most of the PRP literature is not.

So the fair summary is: PRP has much more evidence, mostly about a different question; HBOT has very little evidence, about the right question, and what it found was a benefit in early shedding and inflammation rather than in final survival.

How do PRP and HBOT compare in day-to-day practical terms?

PRP means a blood draw and repeated, often uncomfortable scalp injections over months or years, with lower systemic risk since it's autologous. HBOT means daily chamber attendance for six or seven days, requiring ear equalisation and contraindication screening, as a one-week course. PRP's preparation also varies far more between clinics than HBOT's pressure-and-time protocols.

• Burden. PRP is a blood draw and a set of scalp injections, typically repeated at intervals over months. HBOT is daily chamber attendance for six or seven days.
• Discomfort. PRP scalp injections are genuinely uncomfortable for many people. HBOT is not painful but requires ear equalisation and tolerating enclosure.
• Screening. HBOT requires contraindication screening that a hair clinic is often not the right party to perform. PRP is autologous and carries a lower systemic risk profile.
• Ongoing cost. PRP is usually sold as repeated sessions over years. HBOT is a one-week course.
• Protocol variability. PRP preparation varies enormously between clinics, which is one reason its literature is hard to interpret. HBOT protocols vary less, being anchored to pressure and time.

What would you tell a patient deciding between PRP and HBOT?

Neither treatment is proven to raise the number of transplanted follicles growing at twelve months. PRP has evidence for treating native hair, not graft survival. HBOT's one trial showed less early shedding and folliculitis, with no proven effect on the final result. Paying for both, expecting a compounding benefit, has no support in either literature.

Neither treatment has established that it improves the number of transplanted follicles growing at twelve months. Anyone selling either on that basis is going beyond the evidence.

PRP has a substantial literature supporting its use as a treatment for androgenetic alopecia, with real methodological caveats. If you are interested in PRP, that — treating your remaining native hair — is the use with evidence behind it, and it is a conversation to have with a doctor.

HBOT has one small on-topic trial showing less early shedding and less folliculitis, and no demonstrated effect on the final result. If reduced discomfort and less alarming early shedding in the first fortnight is worth the cost and the daily schedule to you, that is a defensible choice, made with accurate expectations.

The most common error is paying for both on the assumption that they compound into a better result. Nothing in either literature supports that.

Sources

1. Kieling L, et al. Is autologous platelet-rich plasma capable of increasing hair density in patients with androgenic alopecia? A systematic review and meta-analysis. Anais Brasileiros de Dermatologia, 2024;99(6):847-862. pubmed.ncbi.nlm.nih.gov/39013743
2. Xiao C, et al. Meta-Analysis of Efficacy of Platelet-Rich Plasma Combined with Minoxidil for Androgenetic Alopecia. Aesthetic Plastic Surgery, 2024;48(21):4554-4566. pubmed.ncbi.nlm.nih.gov/38789807
3. Fan Z, Gan Y, Qu Q, Wang J, Lunan Y, Liu B, Chen R, Hu Z, Miao Y. The effect of hyperbaric oxygen therapy combined with hair transplantation surgery for the treatment of alopecia. Journal of Cosmetic Dermatology, 2021;20(3):917-921. pubmed.ncbi.nlm.nih.gov/32770782
4. Giardiello F, De Medeiros Quirino L, Brigante R, Chumak M. Hyperbaric Oxygen Therapy for Enhanced Postoperative Recovery in Hair Transplantation. Cureus, 2025;17(12):e99635. doi.org/10.7759/cureus.99635
5. Lee HY, Lee JY, Kim SC, Lee Y. Preliminary Effects of Hyperbaric Oxygen Therapy on Hair Follicle Characteristics in Healthy Subjects. Bioengineering, 2026;13(2):240. doi.org/10.3390/bioengineering13020240

This article summarises published research and standard clinical practice. It is general educational information, not medical advice, and it does not replace the instructions your own surgical team gives you. Where their guidance differs from anything here, follow theirs.