The Best-Researched Ingredients for Prostate Health

Prostate supplements are crowded with ingredients, but only a handful have been tested in people in a meaningful way, and even those rarely deliver what marketing promises. Below we rank the ingredients that appear in the products we reviewed by the strength of the human research behind them, then explain what that research actually shows. Strong research is not the same as a strong benefit: the best-studied herb on this list is also one of the clearest examples of a supplement that does not beat placebo.

Nothing here replaces medical care. Urinary symptoms can have several causes, including infection and prostate cancer, and a doctor can help you decide whether PSA testing is right for you (MedlinePlus).

1. Saw palmetto: well studied, little benefit

Saw palmetto

What it is: berry extract of the Serenoa repens palm. What studies show: dozens of trials, including the one-year STEP trial (Bent et al., 2006) and the dose-escalation CAMUS trial (Andriole et al., 2013), culminating in a 2023 Cochrane review of 27 studies that found little to no benefit for urinary symptoms from an enlarged prostate (Franco et al., 2023). It does not appear to alter PSA. Studied dose: 320 mg per day, up to 960 mg in CAMUS. Cautions: mild digestive upset or headache; avoid in pregnancy (NCCIH). Read more about saw palmetto.

2. Stinging nettle root: some positive trials, needs confirmation

Stinging nettle root

What it is: root extract of Urtica dioica, a traditional European prostate herb. What studies show: mostly open studies plus a few randomized trials of specific extracts; a review said the effect still needed confirmation (Chrubasik et al., 2007). One large single-center trial reported strong benefits that have not been replicated (Safarinejad, 2005), and a nettle and saw palmetto combination showed symptom improvement over 96 weeks (Lopatkin et al., 2007). Studied dose: roughly 120 to 360 mg of extract daily. Cautions: mild stomach upset; check interactions with diuretics, lithium, diabetes and blood pressure drugs. Read more about stinging nettle root.

3. Ashwagandha: good for stress, not a prostate herb

Ashwagandha

What it is: an Ayurvedic adaptogen root. What studies show: some preparations may help stress and insomnia; limited evidence suggests modest testosterone increases (NCCIH; Akhgarjand et al., 2022; Lopresti et al., 2019). No prostate trials. Studied dose: 300 to 600 mg extract daily for stress. Cautions: rare liver injury; avoid in pregnancy, thyroid and autoimmune disease; NCCIH advises people with hormone-sensitive prostate cancer to avoid it. Read more about ashwagandha.

4. Vitamin D3 and zinc: fill gaps, not prostate treatments

Vitamin D3

What it is: the main supplemental form of vitamin D. What studies show: essential for bones and general health; studies on vitamin D and prostate cancer risk are mixed (ODS). Typical dose: RDA 15 to 20 mcg; upper limit 100 mcg. Cautions: excess raises blood calcium. Read more about vitamin D3.

Zinc

What it is: an essential mineral found in meat, seafood, dairy, beans and nuts. What studies show: important for immunity and many enzymes, but zinc products generally did not raise testosterone in a systematic review (Morgado et al., 2024), and there is no good evidence that extra zinc improves prostate symptoms. Typical dose: RDA 8 to 12 mg for adults; upper limit 40 mg (ODS). Cautions: high doses reduce copper absorption and interact with some antibiotics. Read more about zinc.

5. Pomegranate: promising early data, negative controlled trial

Pomegranate

What it is: a polyphenol-rich fruit, used as juice or extract. What studies show: an uncontrolled trial in treated prostate cancer patients reported slower PSA doubling (Paller et al., 2013), but a placebo-controlled trial found no PSA effect (Stenner-Liewen et al., 2013). No evidence for urinary symptoms. Studied dose: 1 to 3 g extract or 250 to 500 ml juice. Cautions: digestive upset; may lower blood pressure (NCCIH). Read more about pomegranate.

6. Tongkat ali and shilajit: testosterone signals, no prostate data

Tongkat ali

What studies show: a meta-analysis of small trials found higher total testosterone, especially in men with low levels (Leisegang et al., 2022). Studied dose: 200 to 400 mg extract. Cautions: may not suit men with prostate cancer; possible insomnia. Read more about tongkat ali.

Shilajit

What studies show: one 90-day placebo-controlled trial of purified shilajit raised testosterone (Pandit et al., 2016). Studied dose: 250 mg twice daily. Cautions: unpurified products may contain heavy metals (Hussain and Saeed, 2024). Read more about shilajit.

7. Boron: early research only

Boron

What studies show: observational links between boron intake and prostate measures, and a tiny hormone study; no clinical trials for prostate outcomes (ODS; Naghii et al., 2011). Typical dose: 3 to 10 mg; upper limit 20 mg. Read more about boron.

Ingredients to approach with caution

Vitamin E

In the SELECT trial, 400 IU of vitamin E daily increased prostate cancer risk in healthy men (Klein et al., 2011). Small amounts near the RDA are a different matter, but avoid high-dose products. Read more about vitamin E.

Iodine and seaweeds

Iodine is essential for the thyroid, but there is no evidence extra iodine helps the prostate. Products that add iodine plus kelp, bladderwrack, wakame or nori without stating amounts can push intake past the 1,100 mcg upper limit (ODS), and kelp has been linked to hyperthyroidism (Gherbon et al., 2019).

The bottom line

The ingredient with the most research, saw palmetto, mostly fails to help, and the ingredients with more encouraging signals are either unconfirmed (nettle root) or aimed at testosterone rather than the prostate. Lifestyle steps and proven medical treatments remain the foundation for urinary symptoms (NIDDK). If you use a supplement, choose one that discloses doses and tell your doctor.