PRP and polynucleotides for hair:
what the evidence supports

What is the difference between PRP and polynucleotides for hair?

PRP and polynucleotides are both injectables placed in or under the scalp skin, but they are different materials with different evidence. PRP is a concentrate of your own platelets, which release growth factors when they are activated. Polynucleotides are chains of purified DNA, and those used in aesthetic medicine are commonly purified from salmon DNA. They were developed for skin quality, and their use on the scalp rests on the idea that they support tissue repair and the blood supply around follicles.

Neither treats the cause of pattern hair loss, which is inherited sensitivity of follicles to dihydrotestosterone (DHT). Prescription medicines such as minoxidil and finasteride remain the foundation of guideline hair loss treatment, started only after a doctor has assessed the scalp and the history. PRP and polynucleotides sit alongside that foundation, which is why diagnosis comes before either.

At this practice the core of a regenerative plan is not an injectable of either kind. It combines autologous micrografting with Regenera Activa, fractional laser stimulation of the scalp and medical therapy where indicated, sequenced by stage, and low-level laser is used as a drug-free first-line option. PRP and polynucleotides are considered as adjuncts where the plan calls for more support.

How is each one prepared and given?

PRP is prepared on the day. A small amount of blood is drawn, spun to concentrate the platelets, and the concentrate is injected into thinning zones of the scalp. Protocols differ between studies and clinics in how concentrated the platelets are, whether the plasma is activated before injection, and how injections are spaced, so one PRP is not automatically comparable with another. The number and spacing of treatments are planned individually.

Polynucleotides are supplied as a sterile product, so no blood draw is needed. They are injected into the scalp skin across the thinning zones. Tenderness, pinpoint bleeding and mild swelling at the injection points are expected after either treatment. Fish or salmon allergy rules polynucleotides out.

At this practice the order is the same for both. Dr Sin Yong takes the history and examines the scalp, usually with trichoscopy, stages the pattern on the Norwood or Ludwig scale, orders blood tests where shedding or female thinning needs them, and writes a plan with the fee. Treatment follows only if the assessment supports it, and progress is reviewed against the starting photographs.

“A miniaturised follicle can be woken. A dead one cannot. The whole discipline of hair regeneration is knowing which one you are looking at.”

Dr Sin YongOn why staging comes before any hair treatment

What does the evidence say about each?

For PRP the evidence is the larger of the two. A 2023 systematic review of nine randomised trials, involving 238 patients, reported higher hair density with PRP than with placebo in androgenetic alopecia. A 2025 review of 43 randomised trials, involving 1,877 participants, rated the evidence as moderate for hair density and for reducing hair loss, found no significant effect on hair thickness, and noted that how the PRP was prepared, including whether it was activated, appeared to influence the response. Its authors called for standardised trials, which is a fair summary: the signal is real, the method is not uniform.

For polynucleotides the evidence is thinner. A 2025 prospective study followed 28 people with androgenetic alopecia who received a series of polynucleotide injections and measured hair diameter and density by dermoscopy. It reported improvement, but it had no untreated comparison group, so it can describe change without showing that the injections caused it. Larger controlled studies would be needed before polynucleotides could be placed beside PRP.

Hair studies need careful reading. Hair density can be measured differently from one study to the next, follow-up is often short compared with how slowly hair cycles run, and the kits and injection spacing used in clinics differ from the protocols in the trials. A positive average in a meta-analysis does not tell any one person how their scalp will respond, which is why progress is compared with your own baseline.

This practice's position follows the evidence. PRP is a recognised adjunct that can be included where it fits a case, and polynucleotides can support a protocol but are never offered as a standalone cure.

Who do they suit, and who should wait?

Both are considered for pattern thinning in which trichoscopy still shows miniaturised but living hairs, in people willing to follow a staged plan and, where advised, to continue medical therapy. In women, thyroid, iron and hormonal contributors are screened first, because female thinning has a longer list of possible causes than male pattern loss. Staging matters because the follicles are the limit: a miniaturised follicle can still respond to support, whereas a smooth, shiny zone with no follicles left is a transplant conversation and is referred for that assessment.

Several situations mean waiting or a different pathway. Pregnancy and breastfeeding are reasons to defer scalp injections. Active scalp infection or inflammation, a bleeding disorder, and blood-thinning medicine are reviewed first. Hair loss that has not been explained, such as shedding after illness or childbirth, low iron or thyroid disease, is investigated before anything is injected, because correcting the trigger is the treatment. Patchy autoimmune loss and scarring alopecia follow their own pathways.

What can neither treatment do?

Neither treatment can recreate a follicle that has gone, change the inherited sensitivity to DHT, or replace the medication that controls it. Pattern hair loss is progressive, so some form of maintenance is usually needed, and medical therapy in particular must be used continuously because stopping it leads to rebound shedding.

Neither is a short cut around diagnosis. Alopecia areata, telogen effluvium and traction alopecia look like thinning but are not pattern loss, and an injectable for the wrong diagnosis only delays the right one. Hair operates in months, not weeks, so progress is judged against baseline trichoscopy and photographs rather than the daily mirror.

Questions worth asking any clinic before agreeing to either: what is my diagnosis and stage, how will progress be measured, what happens if I do not respond, how is the PRP prepared and is it activated, and who performs the injection. A clinic that answers with a package instead of a diagnosis has not yet assessed you.

What are the risks, and when should you call?

Both treatments are injections, so tenderness, bruising, swelling and small bleeding points are common and settle. Less often there are headaches, infection at an injection point, or an allergic reaction, which is why allergies are asked about first. Response varies between people, and an uneven response between zones can occur. Written aftercare sets out what is expected and which signs to report, and the scalp products and medicines you use are reviewed at the same visit so that nothing irritating is added alongside treatment.

Contact the clinic the same day for spreading redness, swelling, discharge or fever, bleeding that does not settle with gentle pressure, or pain that is getting worse rather than easing. Sudden diffuse shedding or new bald patches are reviewed rather than watched.

What determines the fee?

The fee depends on the stage found at assessment, the scalp area and number of zones treated, whether PRP, polynucleotides, laser stimulation or medical therapy are used alone or together, the consumables involved, and whether treatment is staged over time. Singapore's rules for medical advertising prevent prices from being published, and a figure given before the scalp has been examined would be meaningless.

A written quote is given at consultation, after the examination, and the consultation also decides whether treatment is advised at all or whether medication alone, or a transplant assessment, fits your stage better. How fees are quoted explains what a quote contains.