Platelet-rich plasma (PRP) is a treatment that doctors use to accelerate healing in various areas of the body. It may help restore hair growth.

Doctors typically use this treatment when hair loss results from androgenetic alopecia, a common condition that causes hair follicles to shrink. In males, this is called male pattern baldness.

Although PRP is a relatively new approach, there is some scientific evidence to suggest that it can promote hair growth.

In this article, we describe how doctors use PRP to treat hair loss and what researchers say about its effectiveness.

hair loss in a woman who could use PRPShare on Pinterest
A doctor may suggest PRP to treat androgenetic alopecia.

To understand how PRP works, it is important to be aware of the role that platelets play in healing.

Platelets are a component of blood, along with red and white blood cells. When a person sustains a cut or wound, the platelets are some of the body's "first responders" that arrive to stop the bleeding and promote healing.

Researchers theorized that if they could extract concentrated platelets and inject them into damaged areas of the body, they could accelerate healing.

To produce PRP, a medical professional will take a blood sample and put it into a machine called a centrifuge. This machine spins at a rapid rate, which separates the components of the blood. The medical professional then extracts the platelets for injection.

PRP contains a range of growth factors and proteins that speed tissue repair. As some types of hair loss result from damage to hair follicles, researchers initially hypothesized that PRP could help regrow hair by reversing the process that occurs in androgenetic alopecia.

Since then, PRP has become a popular method of restoring hair growth. Doctors have also used PRP to treat injuries to the tendons, muscles, and ligaments, such as those that people sustain during sporting activities.

Sports injuries often affect the knees. Here, learn whether PRP for knee injuries is effective.

In 2019, a team of researchers carried out a systematic review of the research on PRP as a treatment for hair loss. Their findings appear in the journal Aesthetic Plastic Surgery.

The analysis ultimately focused on 11 research papers that included a total of 262 participants with androgenetic alopecia. According to the authors, most of the studies found that injections of PRP reduced hair loss and increased the diameter of hairs and the density of hair growth.

They acknowledged, however, that the treatment is controversial, noting that small sample sizes and low quality of research were among the limiting factors of their investigation.

Another 2019 systematic review, which featured in Dermatologic Surgery, examined the findings of 19 studies investigating PRP as a treatment for hair loss. These studies recruited 460 people in total. According to the authors of the review, most studies reported that PRP treatments led to hair regrowth in those with androgenetic alopecia and alopecia areata.

The authors of an additional review of clinical studies, which the International Journal of Women's Dermatology published, considered PRP to be a "promising" treatment for hair loss, based on their findings.

However, the team noted that because various researchers and clinics use different preparations, session intervals, and injection techniques to administer PRP, its effects can vary.

At this point, without a standardized protocol for injections, the authors explain, it is difficult to conclude that the treatment is effective.

Here, learn about other treatments for thinning hair.

The following steps are an example of a common approach to PRP injections for hair loss:

  • A medical professional draws blood from a vein in the arm.
  • They place the blood sample in a centrifuge.
  • The centrifuge spins the blood, separating its components.
  • A medical professional extracts the platelets using a syringe.
  • A doctor injects the platelets into targeted areas of the scalp.

The entire process may take about 1 hour, and several sessions may be necessary. After receiving PRP treatment, a person can usually return to their regular activities without any limitations.

Certain changes to the diet and daily routine may help promote hair growth or prevent hair loss. Find out more here.

PRP is not a cure for conditions that cause hair loss. For this reason, a person would need to receive multiple PRP treatments over time to maintain hair growth results. The same is true of medications that doctors commonly use to treat androgenetic alopecia, such as topical minoxidil (Regaine) and oral finasteride (Propecia).

The doctor's recommendations for how often a person should have PRP will vary depending on a person's condition and the results of their initial treatment. The doctor may suggest having maintenance injections every 3–6 months once hair loss is under control.

Share on Pinterest
Possible side effects include a headache, mild pain at the injection site, and scalp tenderness.

As the PRP solution consists of a person's own blood components, there are few risks of a reaction to the solution itself.

However, people undergoing PRP treatments for hair loss may experience the following side effects:

  • mild pain at the injection site
  • scalp tenderness
  • swelling
  • a headache
  • itching
  • temporary bleeding at the injection site

Researchers have found evidence that PRP can lead to renewed hair growth. However, due to the limitations of these studies — such as small sample sizes — and the variation in technique and protocol among doctors, further research is necessary to confirm whether PRP is effective.

Doctors and researchers also need to identify the best candidates for PRP and develop universal treatment protocols.

At present, anyone with mild-to-moderate hair loss who is interested in PRP should ask a doctor whether they are likely to benefit from the treatment.