How it works
Head to our comparison tool and select any two supplements from our database. You will instantly see a side-by-side breakdown of:
- Key benefits — what each supplement is primarily used for.
- Recommended dosage — evidence-based dosing ranges.
- Side effects — common and rare side effects to be aware of.
- Evidence rating — how strong the scientific evidence is (strong, moderate, emerging, or weak).
- Best taken — timing, with or without food, and interactions to avoid.
Popular comparisons
Magnesium Glycinate vs Citrate
Vitamin D3 vs D2
Creatine Monohydrate vs HCL
Fish Oil vs Krill Oil
Ashwagandha vs Rhodiola
Zinc Picolinate vs Gluconate
A note on evidence
We rate every supplement based on the quality and quantity of published research. A “strong” rating means multiple randomised controlled trials support the claimed benefit. “Emerging” means early research is promising but more studies are needed. We never rate something as effective based on anecdotes alone.
Supplements are not regulated like medicines. Always check with your GP before starting a new supplement, especially if you take medication. Our tool is for information, not medical advice.