Questions · Hair loss

Hair loss:
30 questions about follicles that can still respond

Medically reviewed by Dr Sin Yong · Last reviewed 7 October 2026 · 10 min read

Published 7 October 2026 · Reviewed by Dr Sin Yong

Hair loss questions divide into sudden shedding, gradual pattern thinning and patches, each with its own work-up. Whether a follicle can still respond decides what non-surgical options make sense and when a transplant referral is more honest. These 30 brief answers link to the fuller pages.

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Questions on this page
  1. What causes male pattern hair loss?
  2. How do I know if my hair is thinning or I'm imagining it?
  3. Can hair grow back once it's lost?
  4. What is the difference between female and male pattern hair loss?
  5. What blood tests are done for female hair loss?
  6. What causes sudden hair shedding?
  7. Does minoxidil work?
  8. What happens if I stop using minoxidil?
  9. What is Regenera Activa?
  10. Does Dr Sin Yong perform hair transplants?
  11. What is trichoscopy and why is it done for hair loss?
  12. What is the Ludwig scale for female hair loss?
  13. Is a receding hairline always male pattern baldness?
  14. Why does minoxidil cause shedding at first?
  15. Can women use minoxidil for hair thinning?
  16. How does finasteride work for hair loss?
  17. Does topical finasteride have fewer side effects than tablets?
  18. What are the side effects of finasteride?
  19. What is the difference between PRP and polynucleotides for hair?
  20. Who should not have polynucleotide injections for hair?
  21. What is H2LT laser treatment for hair loss?
  22. Is a home laser helmet the same as clinic laser for hair?
  23. Where is the tissue taken from for Regenera Activa?
  24. How is alopecia areata different from pattern hair loss?
  25. Can tight hairstyles cause hair loss at the temples?
  26. Does dandruff cause hair loss or thinning?
  27. How can I tell if shed hairs are telogen hairs?
  28. When should hair shedding be investigated further?
  29. Do biotin supplements help with hair loss?
  30. What is the first-line treatment for pattern hair loss?

Hair loss: the answers

What causes male pattern hair loss?

In susceptible men, follicles in the pattern zones respond to dihydrotestosterone by shortening their growth phase, producing finer, shorter hairs each cycle until they stop. Follicles at the back of the head are genetically resistant.

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How do I know if my hair is thinning or I'm imagining it?

Consistent signals: a parting that has widened and stayed widened, a crown visible under overhead light in every recent photograph, temples that have moved, and fine short hairs where full hairs grew. Staging on the Norwood scale replaces guessing.

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Can hair grow back once it's lost?

A miniaturised follicle is alive and still produces fine hair; a follicle that has stopped producing cannot be reopened. Follicle-support treatments act on the first kind, which is why follicle status is assessed first.

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What is the difference between female and male pattern hair loss?

Male loss recedes at the temples and thins the crown (Norwood I to VII). Female loss is diffuse over the crown with a widening part and preserved hairline (Ludwig I to III); women also have more alternative causes.

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What blood tests are done for female hair loss?

Guided by history and examination, but commonly ferritin for iron stores, thyroid function, and other tests where hormonal or systemic contributors are suspected. Bring recent GP results rather than repeating tests.

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What causes sudden hair shedding?

Most often telogen effluvium, triggered by illness, fever, surgery, childbirth, stress, crash dieting or deficiency. Shedding starts two to four months after the trigger, so the cause is often missed; it usually settles once the trigger is corrected.

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Does minoxidil work?

It carries guideline-level evidence in men and women, slowing loss and thickening miniaturised hairs, with the effect maintained only during continued use and an early temporary shed as cycles resynchronise.

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What happens if I stop using minoxidil?

The follicles it was supporting gradually return to their previous cycle, and the hair gained during treatment is lost over the following months. Confirm the cause and agree a long-term plan before starting.

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What is Regenera Activa?

Autologous micrografting: three small punch biopsies from the occipital scalp are disaggregated and filtered into a suspension of progenitor cells, signalling factors and matrix, then injected into the thinning areas in the same visit.

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Does Dr Sin Yong perform hair transplants?

No. He manages the medical and non-surgical side of hair loss and assesses whether relocation is the realistic tool; where a transplant is appropriate, patients are referred to an appropriate surgical specialist.

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What is trichoscopy and why is it done for hair loss?

Magnified examination of the scalp that shows whether thinning zones still hold miniaturised hairs, the fine short hairs that treatment can act on, or whether follicles have gone. Alongside Norwood or Ludwig staging and blood tests where indicated, it decides which options are realistic.

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What is the Ludwig scale for female hair loss?

The standard staging of female pattern hair thinning: diffuse widening of the central parting over the crown, graded I to III, with the frontal hairline preserved. It describes the pattern so that pattern loss can be separated from shedding and followed over time.

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Is a receding hairline always male pattern baldness?

No. A maturing hairline shifts slightly and evenly in early adulthood and then stabilises. Continued temple recession or crown thinning, with finer, shorter hairs in the pattern zones, suggests pattern loss, which is confirmed by scalp examination and Hamilton-Norwood staging rather than by the mirror.

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Why does minoxidil cause shedding at first?

Because it pushes resting hairs out so that new growth-phase hairs can replace them; the hairs that fall first were already due to go. This early shedding is usually a sign the cycle is changing, not that treatment is failing, and stopping during it loses the follicles' chance to respond.

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Can women use minoxidil for hair thinning?

Yes, topical minoxidil is used for female pattern hair loss, but not in pregnancy or breastfeeding, and unwanted facial hair is reported more often in women, so where and how it is applied matters. Because female thinning has several causes, the cause is assessed first.

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How does finasteride work for hair loss?

It blocks type II 5-alpha reductase, the enzyme that converts testosterone into DHT, lowering the scalp DHT that drives follicle miniaturisation. It is a prescription medicine for men, started after a doctor's assessment and side-effect discussion; it is not for women who are or may become pregnant.

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Does topical finasteride have fewer side effects than tablets?

It is designed for lower systemic exposure, and trials report smaller falls in blood DHT, but some is still absorbed. The precautions discussed for the tablet therefore still apply, including sexual side effects, mood changes and lower PSA readings. Which route suits you is a prescribing decision after assessment.

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What are the side effects of finasteride?

Changes in libido, erection or ejaculation in a minority of men, reported mood changes, and lower PSA readings, which matters for prostate screening. Anyone who notices low mood should stop and seek medical advice. These are discussed before any course begins and reviewed at follow-up.

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What is the difference between PRP and polynucleotides for hair?

PRP is a concentrate of platelets from your own blood, injected into the scalp, with several randomised trials behind it. Polynucleotides are purified DNA fragments, commonly salmon-derived, with fewer and smaller scalp studies. Both are adjuncts to an assessed plan; neither revives follicles that have gone.

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Who should not have polynucleotide injections for hair?

Anyone with a fish or salmon allergy, because the polynucleotides used in aesthetic medicine are commonly purified from salmon DNA. Beyond that, they are considered only after diagnosis and staging, as an adjunct where the plan calls for more support rather than as a first step.

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What is H2LT laser treatment for hair loss?

Hair Hyperstimulation Laser Therapy, Dr Sin Yong's low-level laser protocol that directs calibrated laser energy at the scalp to act on the follicle and its growth cycle. It is non-drug and non-invasive, used alongside medical management, and starts with scalp mapping and checks for correctable deficiencies.

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Is a home laser helmet the same as clinic laser for hair?

No. Consumer devices deliver a fixed low-power dose; the clinic protocol applies a higher power density systematically across the scalp after the pattern of loss has been mapped. Neither blocks DHT, so either is an adjunct to medical therapy rather than a plan on its own.

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Where is the tissue taken from for Regenera Activa?

From the occipital and retro-auricular scalp, the back and sides, where follicles are comparatively protected from DHT and the area is well vascularised. Three 2.5 mm punch biopsies are taken under local anaesthetic, processed and returned to the thinning areas at the same visit.

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How is alopecia areata different from pattern hair loss?

Alopecia areata is autoimmune: smooth, sharply bordered round bald patches appear over days to weeks, sometimes with exclamation-mark hairs at the margin. Pattern loss is gradual miniaturisation at the temples, crown or parting. Areata follicles are suppressed, not scarred; extensive disease goes to specialist dermatology.

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Can tight hairstyles cause hair loss at the temples?

Yes. Traction alopecia follows years of tension from tight ponytails, buns, braids, extensions or helmets, classically at the temples and frontal hairline, often with a fringe of fine baby hairs left in front. Early on, follicles are inflamed but intact and regrow once tension stops; continued pulling scars them.

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Does dandruff cause hair loss or thinning?

Not directly, but chronic scalp inflammation from seborrhoeic dermatitis is associated with increased shedding, and the itch-scratch loop adds mechanical breakage. It is a reaction to Malassezia yeast on an oily scalp, not poor hygiene, and is usually managed with an antifungal shampoo routine once psoriasis is excluded.

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How can I tell if shed hairs are telogen hairs?

Look at the root. A telogen hair carries a small white bulb at the end, the mark of a hair released at the close of its resting phase, rather than a broken shaft. Handfuls of such hairs two to three months after a fever, childbirth or crash diet point to telogen effluvium.

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When should hair shedding be investigated further?

When it persists beyond about six months after the trigger has passed, when patches or scalp symptoms appear, or when an episode has unmasked underlying pattern loss, which is common and changes the plan. Ferritin, thyroid and nutrition are screened as perpetuating factors.

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Do biotin supplements help with hair loss?

Only where a true biotin deficiency exists, which is uncommon. Low iron stores, low vitamin D and low zinc are more common contributors, and they are found by blood tests rather than guessed. A supplement taken without a deficiency does not treat the follicle.

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What is the first-line treatment for pattern hair loss?

Long-term guideline medication: topical minoxidil, and oral finasteride for men, started after a doctor confirms the pattern and excludes other causes. In-clinic options such as laser and micrografting are layered around that foundation. Treatment acts on surviving follicles; bare, shiny scalp largely does not respond.

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Other question topics

Answers are brief by design and condensed from the linked pages, where the reasoning, caveats and references sit. They are general information and not a substitute for an examination; a consultation with Dr Sin Yong decides what, if anything, is advised. If something feels wrong after a treatment, read the warning signs and contact the clinic.

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