NutriDex

The Supplement Research Compendium

Supplement–drug interactions

Supplements That Interact with Hormone therapy / tamoxifen

7 supplements in NutriDex have a known or theoretical interaction with hormone therapy / tamoxifen. Grouped by severity below; each links to its full evidence, dosing & mechanism. This is educational and not exhaustive — always tell your doctor or pharmacist about every supplement you take before combining it with medication.

Caution — use only with medical guidance 6

Black Cohosh

Black cohosh safety is uncertain in hormone-sensitive conditions such as breast or uterine cancer; use caution.

Chasteberry (Vitex)

Chasteberry may not be safe with hormone-sensitive conditions such as breast, uterine, or ovarian cancer; use caution.

DHEA

DHEA raises estrogen and androgen levels; avoid with hormone-sensitive cancers and use caution with tamoxifen.

Dong Quai

Possible estrogenic activity may be inadvisable with hormone-sensitive cancers or anti-estrogen therapy.

Fenugreek

Fenugreek has phytoestrogen activity; use caution with hormone therapy or hormone-sensitive conditions.

Red Clover

Red clover has estrogen-like activity; use caution with hormone therapy, tamoxifen, or hormone-sensitive cancers.

Monitor — watch for effects 1

Saw Palmetto

May affect androgen pathways like finasteride and slightly raise bleeding risk; can confound PSA tests.

Each supplement links to its full evidence, dosing, mechanism & citations. See also all medication interaction guides →