Patchy beard: genetics, hormones or alopecia areata? Understanding before considering a transplant

Updated: 7 September 2026 — Dr Khalil El Cadhi, ISHRS Full Member (Dar El Hakim, Djerba).

A sparse or “patchy” beard is, in the vast majority of cases, a matter of genetics — the number and distribution of follicles, local sensitivity to dihydrotestosterone (DHT) — and not a lack of testosterone: a man whose cheeks stay hairless almost always has normal hormones. The beard completes its development at around 25-30, which explains why a young beard still fills in. A round, smooth, well-defined patch, on the other hand, is alopecia areata of the beard, an autoimmune disease that is treated medically and is not transplanted; scars, folliculitis and fungal infections are the other causes to rule out. This article helps you tell these situations apart, explains what a medical treatment can really do, and specifies from when a beard transplant becomes a reasonable option.

Why does the beard grow unevenly?

Because the density and distribution of beard follicles are genetically programmed, and each area of the face responds differently to androgens. Beard hair is androgen-dependent: testosterone is converted there into DHT by 5-alpha-reductase, and it is the sensitivity of each follicle’s androgen receptor — not the circulating hormone level — that decides whether vellus hair turns into terminal hair. Men with a congenital type 2 5-alpha-reductase deficiency are the demonstration: normal testosterone, very poor beard. According to a genome-wide association study published on PubMed involving more than 6,000 people, beard thickness is associated with genetic variants identified for the first time, alongside those for hair shape and baldness (DOI): the “family” beard has a biological basis. Finally, maturation is progressive — chin and moustache first, cheeks and junctions last — and continues until 25-30: before that age, an uneven beard is not necessarily a beard that will stay uneven.

Is it a hormone problem?

Rarely: a testosterone deficiency sufficient to thin the beard is almost always accompanied by other signs (reduced libido, fatigue, loss of muscle mass, erectile problems) and is confirmed by a blood test, not by the look of the beard. Conversely, many men with a sparse beard have androgenetic alopecia of the scalp, proof that their androgens are acting — but not on the right follicles. Taking testosterone or “boosters” without a documented deficiency does not improve a genetically poor beard and exposes you to adverse effects (acne, testicular atrophy, polycythaemia, acceleration of baldness). A hormone work-up is only indicated in the presence of suggestive clinical signs; in a healthy man, examining the beard is enough to guide the diagnosis.

A round hole in the beard: alopecia areata or a simple sparse area?

A genetically sparse area is diffuse, present since always, with normal skin and fine vellus hairs; alopecia areata of the beard is a round or oval patch that appeared over a few weeks, with smooth skin, no scarring, often bordered by broken “exclamation-mark” hairs and white vellus hairs visible on trichoscopy. According to a review published on PubMed in 2023, alopecia areata barbae mainly affects men in their thirties, often starts in the neck and jaw region, and spreads to the scalp in a proportion of cases during the first year; it shares with scalp alopecia areata its autoimmune associations, notably thyroid ones (DOI). The other diagnoses to rule out are tinea barbae (inflammatory patch, pustules, scales — a fungal sample decides), scars from folliculitis or pseudofolliculitis (repeated ingrown hairs, smooth and shiny skin: the follicles there are destroyed), trichotillomania and, more rarely, lichen planopilaris. Trichoscopy, applicable to the beard as to the scalp, distinguishes these situations in a few minutes (DOI). The practical point is decisive: active alopecia areata is not transplanted — the grafts would suffer the same autoimmune attack — but it is treated (topical corticosteroids, intralesional injections, and for extensive forms JAK inhibitors, with regrowth reported in up to 75% within a year in published series), and it often regrows on its own when the patch is single (see our dedicated article on alopecia areata of the beard).

What can a medical treatment do for a sparse beard?

Topical minoxidil is the only medical option that has been the subject of randomised trials on the beard: it stimulates existing follicles, thickens vellus hairs, but does not create a follicle where there is none, and its effect stops when it is discontinued. According to a randomised placebo-controlled trial published on PubMed in 2016, a 3% minoxidil lotion applied for 16 weeks significantly increased the number of beard hairs compared with placebo (DOI); a double-blind randomised trial from 2026 in 69 transgender men on testosterone finds, with the same concentration, a gain in beard density of about 11 hairs/cm² versus 0 with placebo over 12 weeks, with good tolerance (DOI). This use is off-label in France as in Tunisia, requires medical advice, and carries possible adverse effects (irritation, dryness, unwanted hair on contact areas, rarely palpitations). Castor or argan oils, biotin without a documented deficiency, “growth kits” and micro-needling rollers have no solid evidence of efficacy on the beard; trimming length and grooming, on the other hand, really do change the perceived density of a moderately uneven beard.

When does a beard transplant become a reasonable option?

From 25-30 years of age, once the beard has finished developing, on stable genetically hairless or scarred areas — cheeks, moustache-beard junctions, burn or acne areas — in a man whose occipital donor area is sufficient. The transplant brings terminal hair where there is none, which no medical treatment does; it is not conceivable on active alopecia areata, on uncontrolled folliculitis, or before the beard has matured. The grafts come from the back of the head, whose hairs take on the texture of the beard within a few months; volumes range from a few hundred grafts for junctions to more than a thousand for entire cheeks, with regrowth visible from the 3rd-4th month and a result at 8-12 months (the pillar of this silo details density, design and course). Harvesting can be done without shaving the donor area. The reference review on facial hair transplantation stresses that naturalness rests on the design and orientation of the hairs, specific to each area of the face (DOI) — it is this requirement, more than the number of grafts, that distinguishes a successful result.

FAQ

Why doesn’t my beard grow on my cheeks?
Because in many men the cheek follicles are fewer and less sensitive to DHT than those of the chin: it is the most frequent genetic distribution of a sparse beard, and it has nothing to do with a hormone deficiency.

Does a sparse beard mean a lack of testosterone?
Almost never in a healthy man. A testosterone deficiency comes with other signs (libido, fatigue, muscle mass) and is confirmed by a blood test; the beard alone is not a hormonal indicator.

Until what age does the beard keep filling in?
Until about 25-30: cheeks and junctions are the last areas to fill in. Before that age, an uneven beard can still change, which argues for postponing any transplant decision.

How do I know whether a hole in my beard is alopecia areata?
Alopecia areata forms a round, smooth, non-scarring patch that appeared over a few weeks, sometimes bordered by broken hairs; a genetic area is diffuse and has always been there. Trichoscopy at the consultation makes the difference, and alopecia areata is treated medically — never by transplant while it is active.

Does minoxidil make the beard grow?
It thickens and densifies existing hairs — two randomised trials show this with a 3% lotion — but does not create absent follicles, and the effect disappears on discontinuation. It is an off-label use, to be discussed with a physician.

Is a beard transplant possible on acne scars?
Yes, on stable, well-vascularised scar tissue, sometimes in two stages; graft survival there is a little less predictable than on healthy skin. Our article on beard transplantation on scars details the conditions.

Further reading

• Beard transplant: filling the gaps, density and natural design (in French)
• Beard transplant: is the result long-lasting? Regrowth, maintenance and a second densification stage
• Beard transplant on scars (acne, burns): reconstruction and orientation (in French)
• Alopecia areata of the beard: round patches in the beard — causes, course, treatments (in French)
• Trichological consultation: how it works, what trichoscopy shows, when to ask for it (in French)

About the author

Dr Khalil El Cadhi — hair transplant surgeon, MBA Paris-Dauphine, Full Member of the ISHRS (International Society of Hair Restoration Surgery), Dar El Hakim practice (Djerba, Tunisia). He performs FUE and LH-FUE (no-shave transplant) for the scalp, beard and eyebrows, personally carrying out the surgical steps of every procedure.

General information that does not replace a consultation. The diagnosis of a sparse beard, the prescription of a treatment and the indication for a transplant depend on a medical examination; the results described vary from one patient to another and carry risks and limits explained at the consultation.

Do you have an uneven beard and want to know whether it calls for a treatment, a transplant — or simply a little patience? A consultation with trichoscopic examination of the beard makes the diagnosis and ranks the options. → drelcadhi.com

Sources
– Adhikari K, et al. A genome-wide association scan in admixed Latin Americans identifies loci influencing facial and scalp hair features. Nat Commun 2016;7:10815 — PMID 26926045 · DOI 10.1038/ncomms10815 (via PubMed).
– Nwosu A, Miteva M. Alopecia Areata Barbae in a Nutshell. Skin Appendage Disord 2023;9(3):179-186 — PMID 37325278 · DOI 10.1159/000529389 (via PubMed).
– Shakshouk H, Tosti A. Trichoscopy beyond scalp. A narrative review. Int J Dermatol 2023;62(3):416-427 — PMID 35511549 · DOI 10.1111/ijd.16226 (via PubMed).
– Ingprasert S, et al. Efficacy and safety of minoxidil 3% lotion for beard enhancement: a randomized, double-masked, placebo-controlled study. J Dermatol 2016;43(8):968-969 — PMID 26893270 · DOI 10.1111/1346-8138.13312 (via PubMed).
– Wattanawinitchai K, et al. Efficacy and safety of topical 3% minoxidil for facial hair enhancement in transmen: a randomized, double-blind, placebo-controlled trial. J Dermatolog Treat 2026;37(1):2638637 — PMID 41778417 · DOI 10.1080/09546634.2026.2638637 (via PubMed).
– Bared A. Beard Hair Transplantation. Facial Plast Surg Clin North Am 2020;28(2):237-241 — PMID 32312510 · DOI 10.1016/j.fsc.2020.01.010 (via PubMed).
– Pillar article: Beard transplant — density and natural design (drelcadhi.com) · Related articles: Beard transplant — lasting result and second stage · Beard transplant on scars · Bridges: Alopecia areata of the beard · Trichological consultation.