Hair restoration: a dermatologist's guide

Hair restoration is the set of medical and surgical treatments that slow hair loss, regrow hair or move it to where it is missing. Which one fits depends on why the hair is being lost, so every plan starts with a diagnosis. A transplant can restore a receding hairline from inherited thinning, but it does little for an autoimmune condition that is still active.

What causes hair loss?

Dermatologists group hair loss by mechanism, because the mechanism decides the treatment.

• Androgenetic alopecia (pattern hair loss) is the most common form in both men and women. Follicles gradually shrink under the influence of hormones and genes, and the hair they produce becomes finer and shorter.
• Alopecia areata is autoimmune: the immune system attacks hair follicles, usually in round patches. The follicles survive, which is why hair can regrow.
• Scarring alopecias, such as lichen planopilaris, destroy the follicle and replace it with scar tissue. Here the first goal is to stop the inflammation, because lost follicles do not come back on their own.
• Hair shaft disorders affect the hair itself rather than how much of it grows: the strands are fragile, irregular or break easily.

Which treatments exist?

Treatments fall into three groups, often combined.

Medical treatment

For androgenetic alopecia, topical minoxidil and oral finasteride are the most established medicines, and low-level light therapy is also used. A 2021 review in the Journal of Cosmetic Dermatology compared these and other options by efficacy, side effects, adherence and cost, and noted that the lack of standard grading makes direct comparison difficult.

Regenerative and procedural treatment

These treatments aim to support the follicle itself. Platelet-rich plasma (PRP) uses concentrated growth factors from the patient's own blood. Exosomes are tiny vesicles released by stem cells that carry signals for repair; they are newer and the evidence is still early. Erbium lasers are another option: a 2025 systematic review led by Professor Nilforoushzadeh found them effective for density, growth rate and thickness across 12 studies and 344 patients, particularly in combination with minoxidil or PRP.

Surgical treatment

A hair transplant moves follicles from the back of the scalp, where they resist the hormones behind pattern hair loss, to thinning areas. It redistributes hair rather than creating new follicles, so the donor area sets the limit of what is possible. When the scalp itself is inflamed or scarred, preparing the scalp before surgery can matter as much as the operation.

How is the right treatment chosen?

Three questions shape the plan:

1. What type of hair loss is it? Pattern hair loss, autoimmune loss and scarring loss are treated differently, and some need to be calmed before anything else is attempted.
2. Is it still progressing? Medical treatment usually comes first to stabilise loss. Transplanting into an area that is still thinning can leave an unnatural result as the surrounding hair continues to recede.
3. How much donor hair is there? For surgery, the density and quality of the donor area decide how much coverage is realistic.

What does current research add?

Much of Professor Nilforoushzadeh's work at the Skin and Stem Cell Research Center of Tehran University of Medical Sciences sits at this frontier. His group has reported exosome treatment in refractory alopecia areata, lichen planopilaris and hair shaft disorders, compared PRP injection with PRP microneedling in a trial of 40 patients, and grown hair follicles in a 3D bioengineering model. These studies are early: case reports and small trials point to directions worth testing, not to settled treatments. The articles in this guide say plainly where the evidence is strong and where it is not.