Hair growth methods ranked by evidence: from strong to wishful

Search for "how to grow hair back" and you will find everything from prescription medicines to onion juice, rice water, rosemary oil, laser helmets and supplements with long ingredient lists. Some of these have been tested in large, controlled trials over many years. Others rest on a single small study, a lab experiment or simply a good story. Treating them as equal options is how many people lose a year or two, and a good deal of money, while their hair keeps thinning.

This guide ranks the common methods for pattern hair loss (androgenetic alopecia) by the strength of the evidence behind them. It draws on systematic reviews and guidelines rather than marketing claims ¹². It is general information, not a prescription; which method suits you depends on your diagnosis, health and preferences.

The short answer

• Tier 1, strong evidence: topical minoxidil, oral finasteride (men), low-dose oral minoxidil and dutasteride under medical care. Hair transplant surgery is well established for suitable candidates, although it moves hair rather than creating it ³⁴⁵⁶.
• Tier 2, moderate evidence: PRP, low-level light devices, microneedling combined with minoxidil, topical finasteride, and spironolactone for some women ⁷⁸⁹.
• Tier 3, limited evidence: ketoconazole shampoo as an add-on, rosemary oil, pumpkin seed oil, saw palmetto, scalp massage and some supplements ¹⁰¹¹¹².
• Tier 4, wishful thinking for most people: biotin without a deficiency, collagen, coconut oil, onion juice, most "hair growth" shampoos and unproven clinic add-ons.
• Whatever you choose, judge it over six to twelve months, with photos.

First: what "works" means in hair loss

Pattern hair loss is gradual and progressive. Follicles become smaller over time and produce finer, shorter hairs until some stop producing visible hair. A treatment "works" if it slows or halts that process and, in many people, thickens some of the miniaturised hairs. Stability counts as success: if your hair looks the same after a year, when it would otherwise have thinned further, the treatment is doing its job.

No current treatment creates new follicles where they have been lost for many years, and treatments only keep working while they are used. Any product that promises otherwise should be treated with caution.

The evidence also depends on the type of hair loss. Shedding after illness (telogen effluvium) usually settles on its own once the trigger has passed, and alopecia areata has its own set of treatments. This ranking is about pattern hair loss. If you are not sure which type you have, see why am I losing hair first.

Tier 1: Strong evidence

Topical minoxidil. Applied to the scalp, minoxidil has been studied in men and women for decades. Meta-analyses consistently show it increases hair counts compared with placebo ¹. In men, the 5% strength performed better than 2% in a randomised trial ¹³. Early shedding in the first few months is common and usually temporary. See minoxidil in Malaysia and 5% versus 2%.

Oral finasteride (men). Finasteride lowers DHT, the hormone that drives pattern hair loss in genetically sensitive follicles. Large trials show it slows progression in most men and improves hair in many ⁴¹⁴. Sexual side effects occur in a minority and need a frank discussion with the prescriber ¹⁵. It is not used in women who could become pregnant. See finasteride.

Low-dose oral minoxidil. Taken as a tablet at a fraction of the dose once used for blood pressure, oral minoxidil has become a common option for people who find topical products hard to use. Reviews and an international expert consensus support its use under medical supervision, with attention to side effects such as unwanted body hair, ankle swelling and a faster heartbeat ⁵¹⁶. See oral minoxidil.

Dutasteride. A stronger DHT blocker than finasteride, dutasteride performed at least as well as finasteride in men in comparative studies ⁶. It is generally a second-line option chosen by a doctor. See dutasteride.

Hair transplant surgery. For suitable candidates with stable hair loss and enough donor hair, a transplant gives lasting, natural-looking density in the areas treated ¹⁷¹⁸. It moves existing follicles rather than creating new ones, so medical treatment is often still needed to protect the surrounding hair. See FUE versus FUT.

Tier 2: Moderate evidence

Platelet-rich plasma (PRP). PRP involves injecting a concentrate from your own blood into the scalp. Meta-analyses of randomised trials suggest it can improve hair density, and adding it to minoxidil may give a small extra benefit ⁷¹⁹. However, preparation methods vary widely, sessions are repeated, and results differ between people. It is best seen as an add-on. See PRP.

Low-level light devices. Caps, helmets and combs that use red light or low-power lasers showed a modest benefit in a recent systematic review ⁸. They require regular use for months and the effect is generally smaller than medication.

Microneedling with minoxidil. Rolling or stamping tiny needles into the scalp, done safely and combined with minoxidil, gave better results than minoxidil alone in several studies ⁹²⁰. Hygiene and correct needle depth matter, and overuse irritates the scalp.

Topical finasteride. A spray or solution applied to the scalp aims to give much of the benefit of oral finasteride with less effect on the rest of the body. A systematic review found encouraging results, and regulators have approved some products in some countries ²¹. See topical finasteride.

Spironolactone (some women). For women with pattern hair loss, especially with signs of excess androgen, doctors sometimes prescribe spironolactone. Evidence is moderate and it is not suitable in pregnancy ²².

Tier 3: Limited evidence

Ketoconazole shampoo. An antifungal shampoo that helps dandruff and seborrhoeic dermatitis, ketoconazole has some evidence as an add-on in pattern hair loss, mostly from small studies ¹⁰. It is cheap and reasonable as a supporting step, not as the main treatment. See ketoconazole shampoo.

Rosemary oil. One randomised trial compared rosemary oil with 2% minoxidil over six months and found similar, modest increases in hair count ¹¹. That single study had no placebo group and used the weaker minoxidil strength. It is interesting, but it is not equivalent to decades of minoxidil research.

Pumpkin seed oil, saw palmetto and other botanicals. A small randomised trial of pumpkin seed oil capsules showed some benefit over placebo ²³. Reviews of saw palmetto and other natural options describe limited, mixed evidence with variable product quality ¹²²⁴. Herbal does not automatically mean safe: some traditional hair remedies, such as he shou wu (Polygonum multiflorum), have been linked to liver injury ²⁵.

Scalp massage. A small study found that standardised daily massage increased hair thickness, and a survey of users reported perceived benefit ²⁶²⁷. It is harmless and pleasant, but the evidence is thin.

Supplements. A recent network meta-analysis found that some supplements may help pattern hair loss, but the studies were small and varied in quality ²⁸. Supplements make the clearest difference when there is a real deficiency, such as low iron.

Tier 4: Wishful thinking for most people

• Biotin helps people who are truly deficient, which is uncommon. Without a deficiency there is little evidence it improves hair, and high doses can distort some blood test results ²⁹.
• Collagen supplements are heavily marketed for hair, but the evidence for hair benefit is weak ³⁰.
• Coconut oil can reduce damage to the hair shaft, which helps hair look healthier, but it does not affect follicles ³¹.
• Onion juice was studied in a small trial in alopecia areata, not pattern hair loss, and the evidence is very limited ³².
• "Hair growth" shampoos stay on the scalp for a minute or two; most have little evidence for follicles.
• Stem cell and exosome treatments are still experimental, and early studies are small and varied ³³³⁴.

The ranking at a glance

Why combinations are common

Many doctors combine methods because they act in different ways: minoxidil supports the growth phase, finasteride lowers DHT, and PRP or microneedling may add a little more. Studies of combinations generally show better results than single treatments ³⁵. See combination therapy and minoxidil and finasteride together.

Making sense of claims in Malaysia

Malaysian shoppers meet hair claims everywhere, from pharmacy shelves to social media and salon packages. A few quick checks help:

• Is there a randomised, placebo-controlled trial in people with your type of hair loss? Lab or animal studies are a starting point, not proof.
• Does the seller say how long results take? Real treatments need months.
• Is the claim too big? Promises of a total fix, certain results or change "in two weeks" are red flags.
• Who diagnosed you? The right method depends on the cause. A general practitioner or a dermatologist registered with the Malaysian Medical Council can confirm it ³⁶.

The guide to treatments that don't work covers common disappointments in more detail.

A note on safety

Strong evidence for benefit does not mean "no side effects". Prescription options such as finasteride, dutasteride, oral minoxidil and spironolactone need a doctor's assessment, especially if you have heart or blood pressure problems, are planning a pregnancy or take other medicines. Topical products can irritate the scalp. Procedures such as PRP and microneedling should be done with sterile technique by trained staff. Ask what the expected benefit is, what the common side effects are, and what the plan is if it does not suit you.

The bottom line

Hair growth methods are not equal. A small number have strong evidence from years of controlled trials; several have moderate evidence as add-ons; many more rest on very little. For pattern hair loss, starting with a proven option, giving it six to twelve months and using photos to judge progress is a far better use of time and money than cycling through oils and supplements. If you add an extra, choose one with at least moderate evidence, and treat bold promises with healthy scepticism.

Frequently asked questions

What is the most proven hair growth treatment?

For pattern hair loss, topical minoxidil (men and women) and oral finasteride (men) have the strongest and longest record of evidence from controlled trials. Low-dose oral minoxidil and dutasteride are also well supported, under medical supervision.

Does rosemary oil work as well as minoxidil?

One small trial compared rosemary oil with 2% minoxidil over six months and found similar modest results, but it was a single study without a placebo group. That is far less evidence than exists for minoxidil, so rosemary oil sits in the limited-evidence tier.

Is PRP worth it?

Meta-analyses suggest PRP can improve hair density in pattern hair loss, but studies vary in method and quality and sessions are repeated over time. It is usually best seen as an add-on to medical treatment rather than a replacement.

Do biotin supplements help hair grow?

Biotin helps people who are truly deficient, which is uncommon. For most people without a deficiency there is little evidence it improves hair, and high doses can interfere with some blood tests.

Do laser caps and combs work?

Reviews of low-level light devices suggest a modest benefit for some people with pattern hair loss. Results vary and depend on regular use over months.

Does a hair transplant make hair grow?

A transplant moves follicles from the back and sides to thinning areas. It does not create new hair, and medical treatment is often still needed to protect the existing hair around the grafts.

How long should I try a method before judging it?

For proven medical treatments, about six to twelve months with consistent use and comparable photos. If a product promises visible results in weeks, be cautious.

Educational content. Not medical advice.