Finasteride and Minoxidil for Hair Loss in Hong Kong: How They Work

A photo from a family lunch shows more scalp along your parting than you remember, or a hairline that sits higher than it did two years ago. In Hong Kong, a search for a "hair growth pill" or lotion blurs two different medicines into one.

Male and female pattern hair loss are the commonest causes of this kind of thinning, and they usually run in families (NHS). Finasteride and minoxidil are the main treatments for male pattern baldness, and minoxidil is also used by women. The detail below comes from UK product information, a hospital dermatology leaflet, dermatology societies and published studies.

In short

• Finasteride is a daily 1 mg tablet that lowers DHT; minoxidil goes on the scalp. They act in different ways.
• Finasteride needs 3 to 6 months before stabilisation shows, and 12 months is a fair test. Topical minoxidil takes 2 months or more in men and 12 to 24 weeks with the women's foam.
• Sexual side effects were reported by a small share of men in trials, but persistent symptoms after stopping and low mood are also on the label. Stop and seek advice if your mood changes.
• Sudden patches, an itchy or painful scalp, or loss after childbirth, illness or weight loss need a diagnosis before treatment.

How do finasteride and minoxidil differ, and which suits which kind of hair loss?

Finasteride works from the inside. The 1 mg tablet lowers dihydrotestosterone (DHT), a hormone involved in pattern hair loss, and is usually taken once a day, swallowed whole, with or without food (NHS finasteride). It is licensed for men with male pattern hair loss, to increase hair growth and prevent further loss, and not for women, children or adolescents (Propecia SmPC).

Minoxidil is a solution or foam put on the scalp. One described action is moving hairs from the resting phase into the growing phase, though the exact mechanism is not fully understood (Regaine solution SmPC).

The NHS lists both as the main treatments for male pattern baldness, adds that minoxidil can also be used for female pattern baldness, and says women should not use finasteride. Neither works for everyone, and both work only for as long as they are used. They are aimed at the family pattern: a receding hairline, a thinning crown or, in women, a widening parting. If yours looks different, read the section on other causes first. Our hair loss and male pattern hair loss pages list the matching products.

How long before you can judge, and what is the shedding phase?

The waiting times differ by medicine.

Medicine	Used for	When to expect a result
Finasteride 1 mg tablet, daily	Male pattern hair loss	Stabilisation after 3 to 6 months; hair counts up from 6 months; a fair test is 12 months
Minoxidil 5% solution on the scalp, twice daily	Male pattern hair loss	2 months or more before growth appears
Minoxidil 5% foam on the scalp, once daily (UK women's licence)	Female pattern hair loss	12 to 24 weeks; stop if nothing by 24 weeks
Low-dose oral minoxidil (off-label)	Pattern hair loss, specialist use	Studied over 24 weeks
Dutasteride 0.5 mg capsule (off-label for hair)	Prostate (licensed); hair studied	Studied over 24 weeks

With finasteride, three to six months of daily use are generally needed before the loss can be expected to stabilise, and continuous use is recommended to keep the benefit. If you stop, the effects begin to reverse by six months and return to baseline by 9 to 12 months (Propecia SmPC). In the trials, 58% of men on placebo had further hair loss at 12 months against 14% on finasteride (DailyMed label). If twelve months pass with no improvement, further treatment probably will not help (MedlinePlus).

Topical minoxidil can take two months or more of twice-daily use before growth appears. The women's once-daily foam takes 12 to 24 weeks, and the advice is to stop if there is no improvement after 24 weeks (Regaine for Women SmPC). Dermatologists suggest six to 12 months of continuous use before judging minoxidil (AAD).

Then there is the shedding that frightens people. It is most likely minoxidil moving hairs between phases, and it generally starts two to six weeks after you begin and settles within a couple of weeks. If shedding goes on for more than two weeks, stop and see a doctor (Regaine solution SmPC).

What are the side effects of finasteride, including sexual effects and mood?

Sexual effects are what people ask about most, so here are the trial numbers. Decreased libido was reported by 1.8% of men on finasteride against 1.3% on placebo, erectile dysfunction by 1.3% against 0.7%, and a smaller volume of ejaculate by 0.8% against 0.4%. Taken together, 3.8% of men reported a drug-related sexual effect in the first 12 months against 2.1% on placebo, falling to 0.6% over the next four years. The effects went away in men who stopped and in many who carried on (Propecia SmPC).

Reports collected after the medicine reached the market include sexual dysfunction that continued after stopping: lowered libido, erectile dysfunction and ejaculation or orgasm disorders (DailyMed label). These are reports, not trial rates, and they are why the warning exists. Our erectile dysfunction pills guide covers options if erections change.

Mood is the other warning to know. Depressed mood, depression and, less often, suicidal ideation have been reported, and the product information says that if these occur, finasteride should be stopped and medical advice sought. A patient card repeating these points comes in the Propecia pack.

Two further points. The NHS lists breast cancer as a possible risk with long use, and the product information asks men to report lumps, pain, enlargement or nipple discharge promptly. Finasteride also lowers PSA, and the label says to double a reading before interpreting it, so tell whoever orders a PSA test that you take it.

Finasteride passes into semen in very small amounts, and the NHS advises a condom if your partner is pregnant or could become pregnant. Women who are or may be pregnant should not handle crushed or broken tablets.

Is dutasteride used for hair loss?

Dutasteride belongs to the same family as finasteride. Its UK licence covers the symptoms of an enlarged prostate, at one 0.5 mg capsule daily. The same label notes that 5-alpha-reductase inhibitors could reduce hair loss and may induce hair growth in men with male pattern hair loss, though the effect on hair was not formally studied in its phase III programme (Avodart SmPC).

The hair evidence is mixed. A meta-analysis of three randomised trials in 576 men over 24 weeks found dutasteride better than finasteride on total hair count and on photographs, with similar rates of libido change, erectile dysfunction and ejaculation disorders (Zhou et al., 2019). A 2024 systematic review of nine studies also reported larger hair-count gains with dutasteride, yet stated that there is no clear evidence to support dutasteride in male pattern hair loss (Almudimeegh et al., 2024).

Finasteride and dutasteride should not be taken together; the NHS lists dutasteride among the medicines that may not mix with finasteride. Dutasteride is contraindicated in women, and a condom is advised when a partner is or may be pregnant.

What about minoxidil: lotion, foam and low-dose tablets?

Men apply 1 ml of lotion to dry hair and scalp twice a day, up to 2 ml in all, and wash their hands afterwards. Hair can grow where the liquid is transferred, so keep it to the scalp. Scalp irritation is the common side effect (AAD), and the solution contains ethanol and propylene glycol, which can irritate. Regrown hair may disappear three to four months after you stop (Regaine solution SmPC).

Stop and get help for chest pain, a fast heartbeat, faintness or dizziness, sudden unexplained weight gain or swollen hands or feet. If you have known heart disease or an arrhythmia, speak to a doctor before starting. Keep children away from the application site, since infants can grow body hair after contact with it (Regaine for Women SmPC).

Low-dose minoxidil tablets are a different matter. Oral minoxidil began as a blood pressure medicine, and in smaller doses it increases blood flow to the hair roots. A hospital dermatology service assesses patients first, has their pulse and blood pressure checked regularly, and works within a range of 0.625 mg to 2.5 mg, sometimes starting with a quarter of a tablet on alternate days. It is not advised for people already taking medicines to lower blood pressure, alcohol should be reduced, and there is no evidence it is safe when trying to conceive, during pregnancy or while breastfeeding (Gloucestershire Hospitals).

In a retrospective study of 1,404 patients on low-dose oral minoxidil, hypertrichosis (extra hair) affected 15.1%, lightheadedness 1.7%, fluid retention 1.3%, a fast heartbeat 0.9%, headache 0.4%, swelling around the eyes 0.3% and insomnia 0.2%. Fewer than 2% stopped because of side effects and there were no life-threatening events, though the study had no control group (Vano-Galvan et al., 2021). A review of 17 studies called it well tolerated and effective for healthy patients who struggle with topical products, while asking for larger randomised studies (Randolph and Tosti, 2021). In a double-blind trial of 90 men, 5 mg a day by mouth was not shown to beat 5% lotion twice a day on hair density over 24 weeks; 22 of 45 men on tablets grew extra hair (Penha et al., 2024).

What is different for women?

Female pattern hair loss tends to widen the parting, and the temples may recede. It begins at midlife for most women, and minoxidil is the most-recommended treatment (AAD).

The UK once-a-day 5% foam is licensed for women aged 18 to 65, at half a capful daily. In a 24-week trial it regrew 13.4 hairs per square centimetre against 4.3 with a dummy foam,. Facial hair is a common side effect (Regaine for Women SmPC). The evidence we read for women covers 2% and 5% minoxidil.

Finasteride is not indicated for women, and a 12-month placebo-controlled study in 137 postmenopausal women showed no improvement in hair count, self-assessment, investigator assessment or photographs (Propecia SmPC). Women who are or may be pregnant must not handle crushed or broken tablets, and should avoid minoxidil, as should women who are breastfeeding (AAD). Other causes can look like female pattern loss, so a dermatologist should rule them out.

When is hair loss not ordinary pattern thinning?

Some hair loss has a different cause and needs a different route. Sudden or patchy loss is one signal. Alopecia areata usually appears as small, coin-sized, smooth round patches, can come on suddenly, and may itch, burn or tingle first. Four in five people regrow completely within a year without treatment, though it can recur, and it is linked to thyroid disease, vitiligo and type 1 diabetes (BAD).

An itchy, painful, burning or tender scalp, with redness and scaling around the hair bases and most often on the crown, points elsewhere. Lichen planopilaris replaces the hair follicle with scarring, so the loss is permanent. It is two to five times more common in women than men, usually between 40 and 60, and is diagnosed by biopsy (BAD).

Loss after childbirth, a major illness or surgery, cancer treatment or weight loss of 20 pounds or more may regrow on its own, and one person can have more than one cause at once. A dermatologist can order a blood test or scalp biopsy if a disease, vitamin deficiency, hormone imbalance or infection is suspected (AAD). The NHS adds illness, stress and iron deficiency to the temporary causes (NHS).

Topical minoxidil is licensed only for pattern loss on a healthy scalp. It is not for use where there is no family history, where the loss is sudden or patchy, where it follows childbirth or where the cause is unknown, and it should not go on inflamed, infected, irritated or painful skin (Regaine solution SmPC).

Which hair loss medicines does PockDose list?

Medicine	What it is
Finpecia (Finasteride)	1 mg finasteride tablet, once a day, for male pattern baldness; a branded generic.
Finasteride	Generic finasteride 1 mg tablets for male pattern hair loss.
Propecia (Finasteride)	Generic Propecia, which is generic finasteride; 1 mg is the hair-loss dose.
Rogaine (Minoxidil)	Generic Rogaine: minoxidil solution for the scalp, 5% and 10% bottles.
Minoxidil	Minoxidil 5 mg and 10 mg tablets, listed for high blood pressure and also taken by mouth for hair loss.
Dutasteride	Dutasteride 0.5 mg capsules (also sold as Dutas), listed for the prostate and male pattern hair loss.
Avodart (Dutasteride)	Generic Avodart: dutasteride 0.5 mg capsules, listed for the prostate.

Ordering needs no prescription. More on the ingredients is on the finasteride, minoxidil and dutasteride pages.

Dutasteride and oral minoxidil tablets are used for hair outside their licensed uses, which are the prostate and high blood pressure. We cannot guarantee the effect. The licence texts do not cover hair, a 2024 review found no clear evidence for dutasteride in male pattern hair loss, and reviews of oral minoxidil call for larger trials. A hospital dermatology service does use low-dose oral minoxidil under supervision, and the Avodart label says 5-alpha-reductase inhibitors may reduce hair loss.