Sparse eyebrows are not a condition. They are a symptom. The cause may be recoverable (thyroid dysfunction, alopecia areata, nutritional deficiency), or it may be a form of hair loss in which the follicle is already destroyed and may not regrow. The next decision differs between these cases — ask a dermatologist to establish the cause and whether scarring is present before deciding whether permanent makeup is an appropriate camouflage option.
So the safer order is: ask a dermatologist to establish the cause and whether the follicle is damaged, then decide whether permanent makeup is the right tool.
Step one: separate non-scarring from scarring
Dermatology groups eyebrow and eyelash loss under the term madarosis, and professional dermatology resources divide it into two categories that determine the outcome:
- Non-scarring: the follicular structures are retained, and the loss is potentially reversible. This includes alopecia areata, thyroid disorders, nutritional deficiency, and mechanical causes such as trauma or plucking.
- Scarring: caused by deeper inflammation and fibrosis. The follicle is lost, and the loss is more likely to be permanent. This includes frontal fibrosing alopecia (FFA) and discoid lupus erythematosus (DLE).
Why that line matters: with non-scarring loss, hair has a chance of returning once the cause is treated, so tattooing is a camouflage add-on. With scarring loss, the priority is medical management to stop progression, not adding pigment to an area that may still be inflamed.
Step two: a map of common causes
The table below is drawn from dermatology resources and is intended to help you work out which specialist to see:
| Category | Common cause | Distinguishing clue |
|---|---|---|
| Endocrine | Hypothyroidism | Loss of the lateral one-third of the eyebrow (known in the literature as Hertoghe sign); coarse, brittle, thinned hair is also common |
| Endocrine | Hyperthyroidism | Loss can also occur, with hair thinning, breaking and shortening |
| Autoimmune | Alopecia areata | Non-scarring, well-demarcated patches; can affect the eyebrows alone |
| Autoimmune (scarring) | Frontal fibrosing alopecia | Scarring; often involves the eyebrows first, then the frontal and temporal scalp |
| Autoimmune (scarring) | Discoid lupus erythematosus | Scarring; can mimic chronic blepharitis, which delays diagnosis |
| Skin disease | Atopic dermatitis, psoriasis, seborrhoeic dermatitis | Accompanied by itching, scaling and repeated rubbing |
| Mechanical / trauma | Long-term repeated plucking, trichotillomania | Prolonged traction-based removal damages the follicle; whether it recovers depends on whether the follicle has survived |
| Treatment-related | Chemotherapy, radiotherapy, laser, botulinum toxin | Iatrogenic triggers |
| Nutritional | Zinc deficiency, biotin deficiency, protein- and iron-related factors | Must be confirmed by testing, not assumed |
| Infection and other | Staphylococcal infection, herpes simplex, rosacea, fungal infection | Requires targeted treatment |
| Physiological | Ageing | Gradual thinning and reduced density |
How it is diagnosed: primarily history and examination, with trichoscopy (dermoscopy of hair), swabs or fungal culture, skin biopsy where indicated, and blood tests such as thyroid function and vitamin A. None of that is something an artist can do. If the cause is unclear, the next step is a dermatologist, not a PMU studio.
Step three: get biotin right first
Biotin (vitamin B7) appears widely in supplements marketed for hair, skin and nails. Two things need settling before you supplement:
- Whether you are actually deficient. Biotin deficiency can cause loss of eyebrow and eyelash hair, but deficiency has to be confirmed by testing, not assumed.
- That it interferes with laboratory tests. The US Food and Drug Administration has issued a safety communication stating that biotin can significantly interfere with certain lab tests, producing incorrect results that may go undetected. It noted that such supplements may contain biotin at up to roughly 650 times the adequate intake, that affected tests include hormone assays and cardiac markers such as troponin, that reported adverse events have increased, and that it received a report of one patient who died following falsely low troponin results caused by biotin interference.
So if you take a biotin supplement, tell your doctor and the laboratory before any blood test. As for whether biotin helps hair regrow, published guidance notes that evidence of effectiveness is limited — testing and supplementation belong with a doctor.
Step four: when permanent makeup is the right answer
Professional dermatology resources list, among non-specific measures for madarosis: cosmetic camouflage, false eyelashes and eyebrows, tattooing, minoxidil solution, topical prostaglandins and hair transplantation. In other words, tattooing is listed as one camouflage option, not as a treatment.
That gives a clear set of judgements:
- Recoverable cause → treat the cause first; tattooing can run alongside treatment as camouflage, with the clear understanding that it does not stimulate hair growth.
- Scarring cause (FFA, DLE) → medical control of disease progression comes first; tattooing an area with active inflammation needs a medical opinion.
- Long-term plucking or trichotillomania → stop the behaviour first; recovery depends on whether the follicle has survived.
- Age-related density loss → tattooing is a reasonable camouflage choice, provided the semi-permanent nature is accepted.
Step five: if you proceed, what to know about longevity
Peer-reviewed literature describes microblading as superficial micropigmentation, with pigment deposited in the papillary dermis, producing semi-permanent results that typically last about 12 to 18 months. That figure is the better-established one.
Retention differs by technique and by skin, so every figure should be treated as an expectation to verify rather than a promise.
Two further points belong in the pre-procedure conversation: pigment and needle compliance information should be verifiable (EU REACH Annex XVII entry 75 applies to tattooing-purpose mixtures including PMU, and the US FDA states it has not approved any colour additive for injection into the skin), and semi-permanent pigment is not easy to remove — the FDA states plainly that laser removal usually takes several treatments spaced a few weeks apart, that complete removal can take many treatments and in some cases may not be possible. For the full explanation, see Organic vs Inorganic PMU Pigments: What the Labels Actually Mean.
Step six: what you can and cannot do yourself
- You can: take the "why is this happening" question to a dermatologist and have the relevant tests; avoid long-term self-prescribed growth products or supplements before a cause is established; tell your doctor and the lab about biotin before blood tests.
- You cannot: substitute "supplements plus tattooing" for a diagnostic workup; pigment an area with active inflammation; rely on any promised number of years.
To check brow pigments by application area, see ATTO's PMU pigment range. To select cartridges by connection and configuration, see ATTO's PMU cartridge needle range.