[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Herbal products and dietary supplements](https://durgical.com/en/pharmacology/classes/herbal-products-and-dietary-supplements/) › Saw palmetto

# Saw palmetto

## Herbal products and dietary supplements?

Herbal products and dietary supplements

## Pregnancy: avoid?

Avoid in pregnancy. It may be unsafe in pregnancy or breastfeeding.

Berry extract of Serenoa repens, promoted for urinary symptoms of an enlarged prostate. Trials show little or no benefit; it is well tolerated.

Updated Nov 1, 2026

Also called: Serenoa repens, Sabalis serrulatae fructus

## Quick facts

**Group**
[Herbal products and dietary supplements](https://durgical.com/en/pharmacology/classes/herbal-products-and-dietary-supplements/)

**Target**
5-alpha reductase (inhibited in vitro only)

**Used for**
Promoted for urinary symptoms

**Key effects**
Digestive symptoms · Dizziness · Headache

**Monitor**
Urinary symptoms · PSA is not affected

**ATC**
G04CX02

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Clinical What the labels mean

- Safety Contraindications
- Key interactions
- What is monitored
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

In laboratory studies saw palmetto extract inhibits 5-alpha reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT), the same step blocked by finasteride. Studies in men with benign prostatic hyperplasia have not consistently shown lower DHT or enzyme inhibition, which fits the lack of clinical benefit.

- Berry extract is taken by mouth
- 5-alpha reductase is inhibited in vitro
- In men, DHT and symptoms change little or not at all

## Indications

- Promoted for urinary symptoms of benign prostatic hyperplasia: probably not helpful when used alone [Benign prostatic hyperplasia →](https://durgical.com/en/conditions/benign-prostatic-hyperplasia/)

## Adverse effects

### Common

- Digestive symptoms
- Dizziness
- Headache

### Serious (rare, important)

- Delay in evaluation of prostate symptoms if relied on instead of medical assessment

## Contraindications

- No established contraindications; see the precautions

## Key interactions

**Any regular medicines**
No specific interactions are well documented; product content varies

## What is monitored

- Urinary symptoms and standard prostate evaluation
- PSA is not affected, so it remains interpretable

## Pregnancy and breastfeeding

Avoid in pregnancy. It may be unsafe in pregnancy or breastfeeding.

## Nursing care

- Ask every patient about herbal products and supplements and record them with the medicine list
- Encourage evaluation of new urinary symptoms rather than self-treatment
- Teach that «natural» does not mean safe and that supplements are not approved as medicines before sale

## Pharmacokinetics

**Absorption**
Taken by mouth as berry extracts

## Memory aid

Saw palmetto «saws» DHT only in the test tube, not in the prostate.

## Test yourself

Think of the answer, then tap the question to see it.

## Which enzyme does saw palmetto inhibit in laboratory studies?

5-alpha reductase, the enzyme blocked by finasteride.

## What did trials show for saw palmetto in benign prostatic hyperplasia?

Little or no improvement in urinary symptoms when used alone.

## Does saw palmetto change PSA results?

No, it does not appear to affect PSA.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/saw-palmetto/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## What the labels mean

**Pregnancy: avoid**
Avoid in pregnancy. It may be unsafe in pregnancy or breastfeeding.

## Connections

## Related drugs 1

- [Tamsulosin](https://durgical.com/en/pharmacology/tamsulosin/)

## Related conditions 1

- [Benign prostatic hyperplasia](https://durgical.com/en/conditions/benign-prostatic-hyperplasia/)

[← Back to the class: Herbal products and dietary supplements](https://durgical.com/en/pharmacology/classes/herbal-products-and-dietary-supplements/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Saw Palmetto: Usefulness and Safety](https://www.nccih.nih.gov/health/saw-palmetto) (National Center for Complementary and Integrative Health (NCCIH), 2025); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=G04CX02) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/saw-palmetto/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/saw-palmetto/