Laser Caps and Red Light Therapy or PRP for Hair Loss. What the Trials Show and Which to Choose

Written By Sofian Youssef

Both work, and they are not competitors. Low-level laser therapy increased hair density against sham devices across 11 double-blind randomised trials and a 2024 meta-analysis of 3,098 patients. PRP increased density against placebo across 43 randomised trials. A cap is bought once, PRP is a clinic course, and the question is how to layer them on top of medication.

Key points

  • A 2019 meta-analysis in Lasers in Medical Science of 8 studies comprising 11 double-blind randomised trials found low-level laser therapy significantly increased hair density against sham devices, with a standardised mean difference of 1.316, in both sexes and with both comb and helmet devices.

  • A 2024 systematic review and meta-analysis in Dermatologic Surgery of 38 studies and 3,098 patients, 2,930 of them with androgenetic alopecia, found low-level laser and LED therapy increased hair density compared with placebo.

  • A 2023 randomised trial in the International Journal of Trichology of 54 patients found adding laser therapy to minoxidil 5 percent improved density by 14.78 percent against 11.43 percent for minoxidil alone, a difference that was not statistically significant.

  • A 2025 meta-analysis in Dermatology and Therapy of 43 randomised trials and 1,877 participants found activated PRP increased hair density and reduced recurrence against placebo, working best alongside minoxidil.

If you are weighing a device against a clinic course, message us on WhatsApp or email team@thewellnesslondon.com and a doctor will tell you how the 2 fit together for your pattern.

What low-level laser therapy actually does

Low-level laser therapy, also sold as red light therapy or photobiomodulation, uses red light at wavelengths of around 630 to 680 nanometres, delivered by a cap, helmet, headband or comb, for a few minutes several times a week. The light does not heat or cut. It is absorbed by mitochondria in the cells of the follicle and appears to increase cellular energy production, improve blood supply, and prolong the growth phase of the hair cycle. The devices are cleared as safe by regulators in the US and Europe and have no meaningful side effects beyond the tedium of using them.

The evidence is better than most people expect for a device sold online. The 2019 meta-analysis in Lasers in Medical Science pooled 11 double-blind randomised trials and found a significant increase in hair density against sham devices, with the effect present in men and women, with combs and helmets, and over short and long courses. It also found that lower treatment frequency produced a larger effect than higher, which is unusual and suggests more is not better. The 2024 meta-analysis in Dermatologic Surgery extended that to 38 studies and 3,098 patients. Individual trials report density gains of around 17 to 42 hairs per square centimetre over 16 to 26 weeks against sham.

What PRP does that a laser cap does not

PRP delivers concentrated growth factors from your own platelets directly into the scalp at the level of the follicle, in a course of 3 sessions with maintenance. The 2025 meta-analysis in Dermatology and Therapy of 43 randomised trials and 1,877 participants found activated PRP increased density and reduced recurrence against placebo, with pooled gains in earlier analyses of around 27 to 36 hairs per square centimetre, and results best alongside minoxidil.

On the trial numbers the 2 treatments produce gains of a similar order, and neither has been compared with the other in a randomised trial of adequate size. What differs is delivery and depth. A laser cap works from the surface, daily, for as long as you keep using it. PRP works from inside the scalp, in a short course, with a result that fades over 6 to 12 months without maintenance. PRP is a medical procedure requiring a blood draw, a preparation step where quality varies, and a doctor. A cap requires a purchase and a habit. Neither treats the hormonal cause, and both work better on top of the drugs that do.

Send us photographs of your thinning on WhatsApp and a doctor will tell you whether your follicles are the kind either treatment can reach.

Where the laser evidence is weaker than it looks

Two honest caveats. The first is the comparison that matters to most patients, which is laser added to minoxidil rather than laser against nothing. The 2023 randomised trial in the International Journal of Trichology gave 54 patients either minoxidil 5 percent alone or minoxidil with laser twice a week. After 16 weeks density improved by 14.78 percent with the combination and 11.43 percent with minoxidil alone, and the difference was not statistically significant. A 2025 systematic review in the Journal of Dermatological Treatment examined the same question across trials. Laser adds something on top of minoxidil, but less than the sham-controlled trials suggest, because minoxidil is already doing most of the work.

The second is the devices themselves. The trials used specific devices at specific wavelengths and doses. The market sells caps from around $59 to $3,299, and there is no evidence that a $59 cap with a handful of LEDs delivers the dose the trials tested. The 2019 meta-analysis found device type did not affect the result among the devices studied, but the devices studied were regulated ones with documented output. A cheap cap is a bet that its output matches the trials. A doctor cannot verify that for you, and neither can the seller.

How to layer them, and the order

For early to moderate pattern loss the evidence-based approach is not a choice between the 2 but a sequence. Medication first, minoxidil for anyone and finasteride for men who can take it, because both treat the process and both have the largest trial records. A laser device second, as a low-risk daily addition that the meta-analyses support, chosen from the regulated brands at the dose the trials used. PRP third, as a course on top of the first 2, for the patient who wants more density than drugs and light have given or who wants to accelerate.

PRP and laser have been used together in trials. A randomised blinded study cited in the 2023 Annals of Medicine and Surgery meta-analysis combined microneedling, low-level laser and non-activated PRP and reported improved regrowth. No trial isolates what each part added. For a patient the practical point is that the treatments do not conflict, that a cap does not replace a course and a course does not replace a cap, and that a clinic selling PRP to someone on no medication and no device is starting with the most expensive step.

A 5 point check before buying a cap or booking PRP

Work through this before spending on either.

  • Are you on minoxidil, and if a man, have you discussed finasteride. Both come before either of these.

  • Is the thinning area still carrying fine, short hairs. Both laser and PRP act on miniaturised follicles. Neither regrows bare skin.

  • If buying a cap, is it a regulated device from a brand used in published trials, with a stated wavelength around 650 nanometres and documented diode count. If the listing says none of that, it is a cap with lights in it.

  • Will you use it 3 times a week for 6 months. The trials did. A cap in a drawer has no evidence.

  • If booking PRP, is the preparation activated, is a doctor injecting, and is it a course with maintenance rather than a single session.

Our doctors put it this way. A laser cap is the treatment we tell people to buy before they see us. It works, it is cheap over time, and it makes PRP a decision about adding density rather than starting from nothing.

Message us on WhatsApp with what you are already using, your pattern, and photographs, and a doctor will give you a straight answer, including if that answer is a cap and 6 months before you come back.

What neither treatment does

Neither laser nor PRP lowers DHT or treats the hormonal cause of pattern loss, so both fade without the drugs that do. Neither regrows hair where follicles have gone, and neither helps shedding from illness, weight loss or stress, which is a different condition. Laser evidence against minoxidil alone is modest and the cheap end of the device market is untested. PRP evidence is rated low quality with publication bias in the most cautious meta-analysis. Neither has been compared with the other in a trial, and neither is available on the NHS.

What each costs, and the arithmetic over a year

Regulated laser caps and helmets from the brands used in trials cost from around $499 to $1,799 for consumer models, with physician-only devices around $3,500 and cheap unregulated caps from $59. Flagship Harley Street and Mayfair clinics commonly charge £600 to £850 or more per session of hair PRP, with a course of 3 taking a plan past £2,000 and maintenance on top.

The reframing is the timescale. A regulated cap is a one-off purchase used for years. A PRP course is repeated. Over 3 years the cap costs less than a single PRP course, and the evidence for it is not smaller. That does not make PRP a poor purchase. It makes PRP the addition for someone who has already done the cheap steps and wants more, which is the patient the combination trials describe.

Care at The London PRP Clinic by The Wellness is doctor-led and priced below flagship rates, with your exact figure confirmed at the free suitability review, which for many patients ends with advice to start medication and a device and return in 6 months.

Ask about the cost for your hair on WhatsApp and we will explain what the review covers.

The free suitability review

Every enquiry here starts with a free, doctor-led suitability review rather than a booking. A GMC-registered doctor examines your scalp, confirms the type and stage of hair loss, reviews your medication and any device you use, and gives one of two answers. Either you are approved for PRP on top of that foundation, with a clear plan and realistic expectations, or you are not approved yet, with an honest explanation of what to start first and when to reassess.

We decline a meaningful share of the people who enquire. For hair loss that often means recommending a treatment we do not sell before one we do.

Why people choose The London PRP Clinic by The Wellness

  • An 87 percent patient success rate across treatments.

  • A 32 percent average density increase reported in our hair restoration programme.

  • More than 187 five star reviews.

  • Every treatment performed by a GMC-registered doctor.

  • 100 supervised treatments completed by every clinician before they treat a patient here unsupervised.

Frequently asked questions

Do laser caps really work for hair loss

Yes, against sham devices. A 2019 meta-analysis of 11 double-blind randomised trials found low-level laser therapy significantly increased hair density, and a 2024 meta-analysis of 38 studies and 3,098 patients confirmed it. The effect on top of minoxidil is smaller and was not statistically significant in a 54-patient trial.

Is PRP better than a laser cap

Neither has been compared with the other in a randomised trial, and the pooled density gains are of a similar order. PRP acts from inside the scalp in a clinic course, laser from the surface daily at home. They are layers, not alternatives, and both sit on top of medication.

Can I use a laser cap and PRP together

Yes. They do not conflict, and trials have combined them with microneedling and reported improved regrowth, though none isolates what each contributes. The evidence-based order is medication, then a regulated device, then PRP for additional density.

Which laser cap should I buy

One from a regulated brand used in published trials, with a stated wavelength around 650 nanometres and a documented diode count, used 3 times a week for at least 6 months. Consumer models from those brands cost around $499 to $1,799. Cheap caps from $59 have no evidence their output matches the trials.

How long does it take for a laser cap to work

The trials ran 16 to 26 weeks and reported density gains of around 17 to 42 hairs per square centimetre against sham over that period. Judge it at 6 months of consistent use, not 6 weeks, and continue using it to keep the effect.

Does red light therapy replace minoxidil

No. In a 54-patient trial minoxidil alone improved density by 11.43 percent and adding laser took it to 14.78 percent, a difference that was not significant. Minoxidil does most of the work and laser adds modestly to it. Neither replaces finasteride in men who can take it.

References

This article is for general information and does not replace a medical assessment. Speak to one of our doctors before deciding on any hair loss treatment.

Sofian Youssef
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Is PRP Available On The NHS