If your hair is thinning at the crown or along the part, you have probably come across the word DHT. It is a hormone closely linked with pattern hair thinning, and saw palmetto is one of the most studied plant ingredients for it.
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From Anirva, the maker of Hair Radiance. This article is general information, not medical advice. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
- Saw palmetto acts on DHT, the hormone behind pattern hair thinning. In lab studies, it slows the enzyme that turns testosterone into DHT [2][3].
- The effect shows up in people. In a 16-week trial, adults who took saw palmetto by mouth had lower DHT in the blood than adults who took a placebo [5].
- Hair responded in the same trial. 400 mg a day reduced hair fall by up to 29% and raised hair density by about 5% [5].
- The findings repeat across studies. A 2020 review found nine human studies in 381 people, and most reported positive effects [2].
- Hair Radiance contains 240 mg of saw palmetto 4:1 extract. This is inside the 100 mg to 400 mg range the studies used [2][5][6].
This article makes the case step by step. It covers what DHT does to a hair follicle, what saw palmetto does to DHT, and what happened to hair in the human trials. It also covers the amount in Hair Radiance, and safety.
Facts at a glance
| Fact | Detail |
|---|---|
| Ingredient and form | Saw palmetto (Serenoa repens), 4:1 extract [6] |
| Amount in Hair Radiance | 240 mg a day, in 3 capsules [6] |
| Percent of Daily Value | No Daily Value has been set [6] |
| Amounts used in studies | 100 mg to 400 mg a day by mouth [2][5] |
| Kinds of evidence | Human trials by mouth and on the scalp; lab studies of the enzyme; one review of the human studies [2][3][4][5] |
| Human studies cited here | 1 review of 9 studies in 381 people, and 1 later trial in 80 people |
| Adult upper limit | None has been set. Used in research studies for up to 3 years [1] |
| Last reviewed | October 14, 2026 |
What is saw palmetto?
Saw palmetto is a small palm tree, 6 to 10 feet tall. It is native to the southeast coast of North America and the West Indies [1].
The supplement is an extract of the berries. It is made up mostly of fatty acids, which form 70% to 95% of the extract. It also contains plant sterols such as beta-sitosterol [2]. Researchers link the fatty acids with its effect on DHT [2].
How does saw palmetto work for hair?
To see why saw palmetto belongs in a hair formula, start with DHT.
What DHT does to a hair follicle
DHT is a hormone that the body makes from testosterone. An enzyme called 5-alpha reductase does this work [3]. In people whose hair follicles are sensitive to DHT, the follicles slowly shrink, and hair on parts of the scalp becomes thinner [3].
So the question for any hair ingredient is plain. Can it lower the amount of DHT that reaches the follicle? For saw palmetto, the evidence says yes.
In the lab, it slows the enzyme
In lab studies, saw palmetto slows both forms of the 5-alpha reductase enzyme. It also lowers the binding of DHT to its receptors by nearly 50% [2]. The fatty acids in the extract appear to act on the enzyme directly [2].
In people, DHT in the blood went down
A lab result means little until it is seen in people. In a 16-week trial, adults who took saw palmetto by mouth had lower DHT in the blood than adults who took a placebo [5]. Their hair responded too, as the next section shows.
Does saw palmetto help hair growth? What the research shows
The research on saw palmetto and hair is still growing, and so far it points in one direction. In 2020, a review searched for every human study of saw palmetto and hair. It found nine studies with 381 people in total [2].
Five randomized trials and two other studies reported positive effects. The products were taken by mouth or put on the scalp, and they supplied 100 mg to 320 mg of saw palmetto [2]. Extracts are not all made the same way, so results may differ from one extract to another [2].
A 16-week trial of saw palmetto oil (2023)
This trial enrolled 80 healthy men and women aged 18 to 50 with mild to moderate pattern hair thinning. They were placed in four groups for 16 weeks. Two groups used saw palmetto oil each day, as a 400 mg capsule or as a scalp formula. The other two groups used matching placebos [5].
In the capsule group, hair fall dropped by up to 29% from the start of the study, and hair density rose by 5.17%. In the scalp group, hair fall dropped by 22.19%, and hair density rose by 7.61%. No serious adverse effects were seen [5].
A 2-year study in 100 men (2012)
This study enrolled 100 men with mild to moderate pattern hair thinning. Half took 320 mg of saw palmetto a day, and half took 1 mg of the medicine finasteride a day. Doctors compared photographs from the start and from the end of the 24 months [4].
After two years, hair growth had increased in 38% of the men who took saw palmetto, mostly at the crown [4]. The 2020 review adds that hair thinning stopped progressing in 52% of this group [2]. In the finasteride group, hair growth increased in 68% of the men [4].
A placebo-controlled trial in 26 men (2002)
This was the earliest placebo-controlled trial. It tested a softgel with 200 mg of saw palmetto and 50 mg of beta-sitosterol, taken twice a day for up to 25 weeks. Staff who did not know the groups rated 60% of the men on the formula as improved. In the placebo group the figure was 11% [2][3].
Study summary
| Study | People | Saw palmetto a day | Length | Main result |
|---|---|---|---|---|
| Sudeep et al., 2023 [5] | 80 men and women | 400 mg by mouth, or a scalp formula | 16 weeks | By mouth: hair fall down 29%, density up 5% |
| Rossi et al., 2012 [4] | 100 men | 320 mg by mouth | 2 years | More hair growth in 38% |
| Prager et al., 2002 [3] | 26 men | 400 mg by mouth, with beta-sitosterol | Up to 25 weeks | 60% rated improved; 11% with placebo |
| Narda et al., in the 2020 review [2] | 35 men | 100 mg by mouth | 6 months | More hairs in the growth phase than with placebo |
| Zanzottera et al., in the 2020 review [2] | 30 men and women | By mouth, 300 mg per tablet | 6 months | Hair density increased in 83.3% |
How much saw palmetto is in Hair Radiance compared with the studies?
| Source | Amount a day | Notes |
|---|---|---|
| Hair Radiance (3 capsules) | 240 mg of saw palmetto 4:1 extract | From the label [6] |
| 2023 trial | 400 mg of saw palmetto oil | For 16 weeks [5] |
| 2012 study | 320 mg | For 2 years [4] |
| 2002 trial | 400 mg, as 200 mg twice a day | With beta-sitosterol, for up to 25 weeks [3] |
| 6-month trial in the 2020 review | 100 mg | In a capsule [2] |
Hair Radiance provides 240 mg of saw palmetto extract a day. That places it inside the range of 100 mg to 400 mg that produced results in the studies.
The label describes a 4:1 extract. The studies used extracts described by their fatty acid or sterol content, so the amounts are not an exact match [2][5][6]. Their results do not describe Hair Radiance as a whole.
22 ingredients, including 240 mg of saw palmetto
Hair Radiance is a daily three-capsule supplement that pairs saw palmetto with vitamins, minerals, plant extracts and probiotic strains. Every ingredient and amount is listed on the label.
See Hair RadianceIs saw palmetto safe? Safety and interactions
Saw palmetto is well tolerated. Adverse effects are mild and infrequent, and they may include digestive symptoms, dizziness and headache [1]. It has been used safely in research studies for up to 3 years [1]. In the hair studies, no serious adverse events were linked with saw palmetto [2].
Saw palmetto may be unsafe during pregnancy or while breastfeeding [1].
Saw palmetto does not appear to change the results of the PSA blood test, which doctors use to check prostate health [1].
The Hair Radiance directions name blood thinners and hormone medicines as reasons to ask a doctor before use [6].
Saw palmetto is one part of Hair Radiance
Hair Radiance is a daily three-capsule hair growth supplement with 22 ingredients: vitamins, minerals, plant extracts, an amino acid and three probiotic strains. They were chosen to support healthy hair growth, to help promote silky, smooth hair, and to strengthen and maintain healthy hair. Saw palmetto is one of them.
Hair Radiance has not been clinically tested as a finished product. For this reason, we cannot say how its ingredients work together. The studies in this article tested saw palmetto by itself or in other formulas.
If you take Hair Radiance, you are not relying on saw palmetto alone. It is one of 22 ingredients in each serving. Every ingredient and amount is listed on the label [6].
If you are deciding
Here is the case in brief. DHT is the hormone behind pattern hair thinning, and saw palmetto slows the enzyme that makes it [2][3]. In a controlled trial, people who took it had lower DHT, less hair fall and higher hair density [5]. Most of the nine human studies point the same way [2]. If thinning at the crown or the part is your concern, this is the job saw palmetto does in Hair Radiance. The 240 mg amount is inside the range the trials used [6]. The directions are three capsules a day with food [6].
The short version
DHT is the hormone behind pattern hair thinning. Saw palmetto slows the enzyme that makes DHT in lab studies, and in a 16-week trial it lowered DHT in the blood. In that trial, 400 mg a day reduced hair fall by up to 29% and raised hair density. Most of the nine human studies point the same way. Hair Radiance provides 240 mg a day.
Frequently asked questions
Does saw palmetto help hair growth?
How does saw palmetto affect DHT?
How much saw palmetto is used for hair?
How long does saw palmetto take to work for hair?
Can women take saw palmetto for hair?
Yes. The 2023 trial enrolled both men and women [5].
What are the side effects of saw palmetto?
The National Institutes of Health describes saw palmetto as well tolerated. Adverse effects are mild and infrequent [1].
Does saw palmetto work on the scalp or by mouth?
How much saw palmetto is in Hair Radiance?
Each serving of three capsules has 240 mg of saw palmetto 4:1 extract [6].
References
- National Center for Complementary and Integrative Health, National Institutes of Health. Saw Palmetto: Usefulness and Safety. Last updated April 2025. https://www.nccih.nih.gov/health/saw-palmetto (accessed October 7, 2026).
- Evron E, Juhasz M, Babadjouni A, Mesinkovska NA. Natural hair supplement: friend or foe? Saw palmetto, a systematic review in alopecia. Skin Appendage Disord. 2020;6(6):329-337. doi:10.1159/000509905. PMID: 33313047.
- Prager N, Bickett K, French N, Marcovici G. A randomized, double-blind, placebo-controlled trial to determine the effectiveness of botanically derived inhibitors of 5-alpha-reductase in the treatment of androgenetic alopecia. J Altern Complement Med. 2002;8(2):143-152. doi:10.1089/acm.2002.8.143. PMID: 12006122.
- Rossi A, Mari E, Scarno M, Garelli V, Maxia C, Scali E, Iorio A, Carlesimo M. Comparitive effectiveness of finasteride vs Serenoa repens in male androgenetic alopecia: a two-year study. Int J Immunopathol Pharmacol. 2012;25(4):1167-1173. doi:10.1177/039463201202500435. PMID: 23298508.
- Sudeep HV, Rashmi S, Jestin TV, Richards A, Gouthamchandra K, Shyamprasad K. Oral and topical administration of a standardized saw palmetto oil reduces hair fall and improves the hair growth in androgenetic alopecia subjects: a 16-week randomized, placebo-controlled study. Clin Cosmet Investig Dermatol. 2023;16:3251-3266. doi:10.2147/CCID.S435795. PMID: 38021422.
- Anirva. Hair Radiance Supplement Facts label and product page. https://anirva.com/pages/hair-growth-supplement-with-probiotics (accessed October 7, 2026).
