Optimum Nutrition

The range is led by Gold Standard 100% Whey, with isolate, casein, ready-to-drink shakes and energy drinks alongside.

Gold Standard 100% Whey is the reference product most other whey powders get compared against, and it is stocked in a range of tub sizes and flavours — the larger tubs are cheaper per serving, but a smaller one is the sensible way to test a flavour first. The isolate versions are filtered further for more protein and less lactose per serving and cost more; casein is the slow-digesting option. Check the panel for protein per serving rather than per 100g, since scoop sizes differ between the lines. See whey protein and all protein powders.

Order by 3pm Monday to Friday for same-day dispatch. Tracked UK delivery is a flat £5, and free on orders over £120.