In short. PRP therapy is a course of injections of the patient’s own platelet-rich plasma into the scalp. The procedure does not remove the hormonal cause of balding, but it can thicken existing hairs and extend the growth phase. It works best in the early stages of thinning and in combination with baseline therapy. Where the follicle has already died, plasma is powerless: new hair will not appear out of nothing.
PRP is one of those procedures surrounded by the most confusion. Some people expect it to grow new hair on a bald patch, others call it a waste of money. Both positions are inaccurate. Plasma therapy has a narrow but entirely real zone of benefit, and the key question is not whether PRP works, but whether it works in your particular situation.
Below we break down what is actually injected under the scalp, what it affects, what clinical studies show, and when a trichologist will advise a different approach. This material will help anyone who has noticed the first signs of thinning and is weighing the options.
What PRP is and what actually enters the scalp
PRP stands for platelet-rich plasma, meaning plasma enriched with platelets. It is not a pharmacy drug and not a vitamin cocktail. It is a fraction of your own blood, separated in a centrifuge immediately before the procedure.
The sequence is as follows. A nurse draws 15 to 30 ml of venous blood into a tube with an anticoagulant. The tube goes into a centrifuge, where blood separates by density into three layers: red cells at the bottom, a thin intermediate layer of white cells and platelets, and clear plasma on top. The doctor collects the upper fractions, and those are what go into the injections.
In the finished concentrate, the platelet count is usually 3 to 5 times higher than in whole blood. Platelets interest a trichologist not because they stop bleeding, but because of their alpha granules. These store signaling proteins: platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), transforming growth factor (TGF-beta), insulin-like growth factor (IGF-1) and epidermal growth factor (EGF).
Because the material is autologous, meaning taken from the patient, the risk of allergy or an immune response is minimal. This is the method’s main advantage over any synthetic injectable cocktail.
How plasma affects the hair follicle
A hair lives in cycles: an active growth phase (anagen), a short transitional phase (catagen), and a resting phase followed by shedding (telogen). In androgenic alopecia, under the influence of dihydrotestosterone, anagen grows shorter with each cycle and the follicle gradually miniaturizes: instead of a thick pigmented hair, a thin colorless vellus hair grows.
Platelet growth factors act on this process through several pathways at once. VEGF stimulates the formation of new capillaries around the follicle, so it receives more oxygen and nutrients. IGF-1 and PDGF support the cells of the dermal papilla, the structure that governs the growth cycle. Together this extends the anagen phase and nudges dormant follicles toward waking up.
One important detail: plasma affects the environment around the follicle, not the hormonal cause of balding. It does not change dihydrotestosterone levels. That is why PRP is viewed as supportive therapy rather than a replacement for drugs that block the hormonal mechanism.
How a session goes, from blood draw to the last injection
The whole procedure takes about 45 to 60 minutes including preparation. No hospital stay is needed, and you return to your usual routine right after the session.
- Examination and trichoscopy: the doctor assesses density, the ratio of thin to thick hairs, and skin condition. Without this step you cannot later evaluate the dynamics.
- Blood draw: 15 to 30 ml from a vein, as in a routine blood test.
- Centrifugation: 5 to 15 minutes depending on the protocol and equipment.
- Skin preparation and pain relief: antiseptic and, if needed, a topical anesthetic cream.
- Injections: with a fine needle to a depth of 3 to 5 mm, spaced roughly 1 cm apart across the thinning area. This takes 15 to 20 minutes.
Does it hurt and what is allowed afterward
Most patients describe the sensation as tolerable tingling. The most sensitive areas are the frontal hairline and the temples. Topical anesthesia removes most of the discomfort.
Right after the session you may notice redness, mild swelling and a feeling of tightness in the skin. This passes within a few hours, less often within a day. For the first day, avoid washing your hair, visiting a sauna or pool, and training to heavy sweating. Skip alcohol and blood-thinning agents for 2 to 3 days before the procedure and for a day after it.
Who gets the best results from PRP
Plasma therapy performs best where the follicle is still alive but working at half strength. The main scenarios:
- Early and moderate androgenic alopecia: Norwood stages I to III in men, Ludwig stages I to II in women. Hair has become thinner and the part wider, but there are no fully bald zones yet. More on the mechanism in the article on androgenic alopecia.
- Chronic diffuse shedding after the underlying cause has been stabilized. When iron, thyroid function and diet are already under control, and telogen effluvium has left visible thinning behind, plasma speeds up the recovery of density.
- Preparation for a transplant and the period after it. PRP improves blood supply to the recipient area and may reduce the extent of temporary shedding of transplanted hairs.
- Patients for whom systemic drugs are contraindicated: women planning a pregnancy, or people who do not tolerate standard therapy.
The common denominator in all these cases is the presence of living, if weakened, follicles. If you are unsure which group you belong to, use a simple guide: does at least a thin vellus hair still grow in the problem area. It also helps to understand how much hair loss per day is normal, so you do not confuse seasonal fluctuations with a real problem.
When PRP will not work
An honest conversation about limits saves patients money and time. Plasma therapy will not deliver results in these situations:
- Fully bald zones. If the skin is smooth and shiny, the follicular structures there have already been replaced by connective tissue. There is nothing left to stimulate.
- Late Norwood stages (V to VII). Here the question is settled by a hair transplant, and plasma can at best support the preserved areas.
- An unidentified cause of shedding. Iron deficiency, thyroid dysfunction, an autoimmune process: as long as the cause is active, injections give a short and unstable effect.
- Scarring alopecias. In these the follicle is destroyed irreversibly, and no growth factors change that.
- Expecting it to replace medication. If a patient counts on a PRP course and full refusal of baseline therapy in active androgenic alopecia, the thinning will continue.
What the research shows
The evidence base for PRP is uneven, and that is worth saying plainly. Systematic reviews and meta-analyses mostly record a positive effect, but studies differ in plasma preparation protocols, the number of sessions and the ways density is measured.
A 2023 meta-analysis of randomized controlled trials showed a statistically significant increase in hair density at 3 and 6 months compared with placebo (PubMed). Another meta-analysis assessed PRP combined with minoxidil across 6 studies and 343 participants: the combination delivered better hair density and thickness than either method alone (PubMed).
At the same time, authors of more recent reviews stress the high heterogeneity of studies and probable publication bias, meaning negative results reach print less often (PubMed). The practical conclusion for a patient: the effect is real, but moderate and not guaranteed. It is reasonable to expect thicker hair and a gain in density, not a visual return of the hairstyle you had ten years ago.
One more observation from practice: results are better documented with trichoscopy before and after the course. A subjective impression in the mirror is deceptive, because changes accumulate slowly and gradually start to feel normal.
How many sessions you need and when results appear
A typical starting course is 3 to 4 procedures at intervals of 3 to 4 weeks. After that you move to a maintenance schedule: one session every 4 to 6 months. The exact plan depends on the stage, your age and what other methods you are using.
The timeline of expectations looks roughly like this. In the first 4 to 6 weeks there are no visible changes, and sometimes shedding even increases slightly, which is a normal follicular response to stimulation. From the second or third month, daily hair loss decreases. Most patients notice visual thickening at 4 to 6 months, and that is exactly when a follow-up trichoscopy makes sense.
Below is an approximate comparison of PRP with other approaches a trichologist considers in the same situation.
| Method | What it affects | Who it suits | Main limitation |
|---|---|---|---|
| PRP plasma therapy | Nutrition and activity of existing follicles | Early and moderate stages, living vellus hair in the thinning area | Does not change the hormonal cause, requires maintenance sessions |
| Minoxidil | Longer growth phase, local blood flow | Most patients with thinning, both sexes | Effect disappears after stopping, needs daily application |
| Anti-DHT medication | The hormonal mechanism of balding | Men with confirmed androgenic alopecia | Prescription only, requires monitoring for side effects |
| Hair transplant | Moving your own follicles into the bald area | Stable late stages, zones with no hair | Surgical procedure, requires a sufficient donor area |
PRP and minoxidil do not compete, they complement each other: the first works in courses and supports nutrition, the second works daily and keeps the hair in its growth phase.
Safety, side effects and contraindications
Autologous material makes this one of the safest procedures in injectable trichology. Typical adverse events are minimal and temporary: redness, swelling, small bruises at injection sites, a brief headache, a feeling of heaviness in the scalp. All of this passes within 1 to 3 days.
The list of contraindications is standard for injectable techniques:
- Blood clotting disorders and ongoing anticoagulant use.
- Acute infections, fever, inflammatory or pustular processes on the scalp.
- Active cancer and blood diseases.
- Pregnancy and breastfeeding, due to a lack of data rather than proven harm.
- Uncontrolled diabetes and severe autoimmune conditions.
Before a course, the doctor usually orders a complete blood count and a coagulation panel. If a clinic offers plasma therapy without an examination, tests and trichoscopy, that is a reason to ask additional questions. A sensible start is a trichologist consultation with diagnostics, and only then a choice of method.
Frequently asked questions
How long does the PRP effect last and do you need to repeat the course?+
The effect of a starting course of 3 to 4 sessions holds for roughly 4 to 6 months, after which maintenance procedures are needed. Plasma therapy does not change the hormonal cause of balding, so without maintenance and baseline therapy density gradually returns to its starting point.
Can PRP be done on a completely bald area?+
No. If the skin is smooth and not even a thin vellus hair grows on it, the follicular structures have already been replaced by connective tissue. Growth factors stimulate living follicles, but they cannot create new ones. In that situation a transplant is discussed.
Can plasma therapy be combined with minoxidil and anti-DHT drugs?+
Yes, and this is the most common scenario. Meta-analyses show that PRP combined with minoxidil gives better hair density and thickness than either method alone. The doctor defines the combination plan after diagnostics.
How many sessions are needed and how quickly will results be visible?+
The starting course is 3 to 4 procedures at intervals of 3 to 4 weeks. Most patients notice reduced shedding in the second or third month, and visual thickening at 4 to 6 months. Trichoscopy before and after the course helps assess changes objectively.
Do plasma injections into the scalp hurt?+
Patients describe the sensation as tolerable tingling. The most sensitive areas are the frontal hairline and the temples. A topical anesthetic cream removes most of the discomfort, and the injection part itself lasts 15 to 20 minutes.
Will PRP help with hair loss after stress or illness?+
Yes, but as a supporting method. First the cause has to be addressed: iron deficiency, thyroid dysfunction, the aftermath of an infection. Once things are stable, plasma therapy speeds up the recovery of density, whereas with an active cause the effect is unstable.
Is the procedure safe and what are the contraindications?+
The material is autologous, so the risk of allergy is minimal. Contraindications: blood clotting disorders and anticoagulant use, acute infections and inflammation on the scalp, active cancer and blood diseases, pregnancy and breastfeeding, uncontrolled diabetes.