UK Supplement Trends — May 2026: Magnesium returns

Part of The Formulation Index, Supplement Factory’s monthly read on what UK brands are actually briefing us to make.

May saw the market’s defining active reassert itself. Magnesium surged back, up twenty-seven points to 39%, while the winter vitamin base cooled hard, Vitamin D3 down twenty-seven points and Vitamin B12 down twenty-four. That contrast, Magnesium rising as the vitamins fall, captures the shape of late spring.

Ingredient in focus: Magnesium

Magnesium’s rebound is a reminder of why it is the anchor of the UK market. Where the vitamins swing with the seasons, immune demand in winter, skin demand before summer, Magnesium’s appeal is year-round: sleep, recovery, relaxation and hydration do not go out of season. Its sharp return to the top in May, against a falling vitamin base, shows the difference between a seasonal active and a structural one. For a brand, that reliability is exactly why Magnesium is the safest base to build a functional product around.

What else moved

The Vitamin D3 fall is textbook: as summer sun arrives, briefs for the “sunshine vitamin” ease, a clean example of the market tracking real-world behaviour. Meanwhile Creatine held at 18% and Collagen at 19%, the functional and beauty layers staying firm beneath the seasonal vitamin swings.

What it means for brands

May underlines a core planning principle: know which of your actives are seasonal and which are structural. A formula built on Vitamin D alone will ride a predictable annual wave; one anchored on Magnesium has year-round relevance. The strongest products usually combine the two thoughtfully, a stable structural base with a seasonal active layered on for timing. Understanding which is which is the difference between a product that sells all year and one that sells for a quarter.

The base was steadying, and it was about to build toward the strongest broad surge of the year.

The Formulation Index is built from Supplement Factory’s own formulation quotes, actives only, each ingredient counted once per quote. Explore the live Index →