Why this topic matters
Small studies, animal research or research on one standardised extract cannot automatically prove that a different commercial blend works. Marketing claims should match the evidence and the claims authorised for that market.
Herbal ingredients can interact with medicines, affect blood pressure or blood clotting, and create risks before surgery. Men with health conditions or multiple medicines should seek professional advice before use.
Factors to review
- Quality and relevance of human studies
- Exact extract, dose and finished-product testing
- Interactions and contraindications
- Legality of the claim in the target market
A practical starting plan
- Look beyond testimonials and before-and-after stories
- Check whether research matches the exact product
- Ask about interactions with medicines
- Avoid products promising to treat disease
- Stop and seek advice after a suspected adverse reaction
Choose your local guidance
England
NHS care and GB claims context
Use the England edition for NHS routes and Great Britain food-supplement advertising context.
Republic of Ireland
HSE care and Irish claims context
Use the Ireland edition for HSE routes and FSAI/Irish food-supplement context.
Questions and answers
Does one positive study prove a supplement works?
No. Study quality, size, replication, dose and whether it tested the same product all matter.
Are herbal ingredients free from interactions?
No. Some can interact with medicines or be unsuitable with certain conditions.
Can testimonials count as evidence?
Testimonials describe individual experiences but cannot establish effectiveness or safety.