Medication questions Treatment and getting started
Do natural DHT blockers work for hair loss?
Short answer
The evidence is limited. A few small trials of saw palmetto, pumpkin seed oil and rosemary oil report improvements in hair counts, but the studies are short, often small and sometimes industry-funded, and reviewers say larger, higher-quality trials are needed. None is a licensed UK medicine for hair loss. "Natural" does not mean risk-free or tested, and they are no substitute for seeing a doctor about hair loss.
Key facts
- Supplements are regulated as food in the UK, not as medicines. They do not need to show they work for hair loss before sale.
- Saw palmetto: a systematic review of 5 randomised trials and 2 cohort studies concluded that robust, high-quality data are lacking.
- Pumpkin seed oil: one 24-week trial in 76 men reported a larger hair-count rise than placebo. It is one small trial.
- Rosemary oil: one 6-month trial in 100 people compared it with minoxidil 2% and found no significant difference between them at 6 months.
- None of these are DHT blockers in the sense that finasteride is a licensed medicine.
What "natural DHT blocker" means
Most "natural DHT blockers" are plant extracts claimed, usually from laboratory research, to inhibit 5-alpha-reductase, the enzyme that makes dihydrotestosterone (DHT). A lab effect does not mean a hair effect in a person. The two licensed or prescribed 5-alpha-reductase inhibitors are explained in what are DHT blockers.
In the UK, food supplements are regulated as food and not as medicines. They do not need MHRA approval before sale, and the seller is responsible for their safety. Products registered as traditional herbal medicines carry a THR number, but that is based on traditional use, not on trials showing they work. Our guide to saw palmetto and finasteride covers how this applies in practice.
What the studies show
Saw palmetto. A 2020 systematic review of 5 randomised trials and 2 prospective cohort studies (Evron and colleagues) found improvements in hair measures with oral and topical products at 100 to 320 mg, with no serious adverse events, but concluded that robust, high-quality data are lacking and that larger randomised trials are needed. The US National Center for Complementary and Integrative Health says the evidence for male-pattern hair loss is too limited to allow conclusions. See does saw palmetto help hair loss.
Pumpkin seed oil. A randomised, double-blind trial in 76 men with mild to moderate androgenetic alopecia gave 400 mg a day or placebo for 24 weeks (Cho and colleagues, 2014). Hair count rose by about 40% with pumpkin seed oil against about 10% with placebo, and adverse effects did not differ between groups. It was a single, small trial.
Rosemary oil. A randomised comparison of rosemary oil and minoxidil 2% in 100 people over 6 months (Panahi and colleagues, 2015) found significant hair-count increases in both groups at 6 months and no significant difference between them; scalp itching was more frequent with minoxidil. A 2024 review of natural alternatives, including rosemary, peppermint, tea tree, green tea, pumpkin seed oil and saw palmetto, concluded that more research is needed to establish efficacy.
Pooled analyses. A 2025 network meta-analysis of 19 randomised trials (1,658 patients, 16 supplements) found that some supplements improved hair density against placebo and that all were well tolerated, but its authors also said larger, high-quality trials are needed to verify the findings.
Limits to keep in mind
Small and short. Most trials involve dozens or low hundreds of people over 3 to 6 months, which is shorter than the timescale for judging any hair treatment.
Which product? Trials test a specific extract at a specific dose. A shop-bought product may contain something different, and the labelling is not checked like a medicine.
Self-reported benefit. Some outcomes are the person's own rating, not measured hair counts.
Not a replacement. The British Association of Dermatologists and the NHS name finasteride and minoxidil as the licensed treatments for pattern hair loss. A supplement is not a substitute for finding out why you are losing hair, and for women or people with sudden or patchy loss, a GP or dermatologist should look at the cause.
Interactions and safety. Saw palmetto may be unsafe in pregnancy or while breastfeeding, according to NCCIH, and you should tell your prescriber and any surgical team about every supplement you take.
What to do
If you are curious about a supplement, tell your prescriber or pharmacist, choose a product from a seller you can identify, and judge it over months with photographs, not the mirror; see how to tell if hair loss treatment is working. If you want an honest view on your options, including no medicine, a GMC-registered doctor can give it in the free online assessment.
Want an answer for your own situation?
A GMC-registered doctor can review your history and medicines and tell you what would suit you, including whether treatment is right for you at all. The assessment and review are free.
Start your free assessment →Related questions
Do natural DHT blockers work?
The evidence is limited. Small trials of saw palmetto, pumpkin seed oil and rosemary oil report improvements, but reviewers say high-quality, larger trials are needed. None is licensed in the UK as a hair loss medicine.
Is saw palmetto a DHT blocker?
It is described as inhibiting 5-alpha-reductase in laboratory research, but the evidence in people with hair loss is limited, and it is sold as a food supplement, not a medicine.
Is rosemary oil as good as minoxidil?
One 6-month trial of 100 people found no significant difference between rosemary oil and 2% minoxidil in hair count, but it is a single small study and does not establish that they are equivalent. Minoxidil 5% for men and 2% for women are licensed in the UK, rosemary oil is not.
Are natural DHT blockers safe with finasteride?
There is no good evidence either way, and the mechanisms may overlap. Tell your prescriber about every supplement you take. See saw palmetto and finasteride together.
Are hair supplements regulated in the UK?
As food, not as medicines. There is no pre-sale approval, and the seller is responsible for safety. A THR number on a herbal product means it is registered for traditional use, not that trials show it works.
Sources
- Evron E et al. Natural hair supplement: friend or foe? Saw palmetto, a systematic review in alopecia. Skin Appendage Disord 2020 (PMID 33313047)
- Cho YH et al. Effect of pumpkin seed oil on hair growth in men with androgenetic alopecia: a randomized, double-blind, placebo-controlled trial. Evid Based Complement Alternat Med 2014 (PMID 24864154)
- Panahi Y et al. Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. Skinmed 2015 (PMID 25842469)
- Bin Rubaian NF et al. An overview of commonly used natural alternatives for the treatment of androgenetic alopecia, with special emphasis on rosemary oil. Clin Cosmet Investig Dermatol 2024 (PMID 39524109)
- Zhou L et al. Effects of dietary supplements on androgenetic alopecia: a systematic review and network meta-analysis. Front Nutr 2025 (PMID 41561175)
- NCCIH: Saw palmetto
- GOV.UK: Food supplements
- GOV.UK: Traditional herbal registration (THR)
Facts checked against these sources on 22 October 2026. This page is general information, not personal medical advice. Read our editorial policy.