Storing and using: frequently asked questions
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How should supplements be stored?
Most supplement labels ask for storage somewhere cool and dry, out of direct sunlight, with the lid closed between uses, and always out of the reach of children.
Heat, damp and light are the main things that can degrade a supplement’s stated potency over time. Some forms have their own instructions: probiotics and certain liquids or oils may need refrigeration, especially after opening, while gummies can soften or stick together in warm conditions. The specific storage line printed on a product’s own label always takes priority over general guidance, since it reflects how that particular formulation was tested to keep its stated potency.
Can a supplement be used after its best-before date?
Usually yes, in the sense that it is not automatically unsafe: a best-before date is about quality, not safety.
UK food labelling guidance states that “after the best before date, the food is usually safe to eat but may not be of the same quality”; for a supplement, that mainly means its stated potency may have gradually declined (GOV.UK: Best before and use-by dates, checked 22 September 2026). This is general food labelling guidance, not specific safety advice for any one supplement or ingredient. If a product shows any sign of damage, an unusual smell, or damp packaging, that is a separate reason for caution regardless of the printed date.
If you take medication, are pregnant, or have a health condition, check with a pharmacist or GP first.
Source: GOV.UK: Understanding food labelling — best before and use-by dates (checked 22 September 2026)
What does "take with food" on a label mean?
“Take with food” is an instruction about how to take the dose, not a claim about what the product does.
It is usually printed because the ingredient is better absorbed alongside a meal (common for fat-soluble nutrients such as vitamins D, E and K, and fish oil), or because taking it on an empty stomach is more likely to cause mild stomach discomfort for some people. It describes how the manufacturer’s directions say to take the product. Where a label gives a specific instruction like this, we read it as part of understanding the product, but it plays no part in the price-per-dose calculation, which is based purely on the amount and the price.
Why do labels say "do not exceed the stated dose"?
Because UK law requires it: food supplement labels must carry “a warning not to exceed the stated recommended daily dose”.
This is one of the fixed pieces of information every supplement label has to show, alongside the ingredient amounts and other required wording, coming from the Food Supplements (England) Regulations 2003, regulation 6(2)(c) (equivalent rules apply across the UK). It is standard, required wording rather than something specific to any one product’s formulation, and applies equally to a product with a wide margin of safety and one with a narrower one — the label does not distinguish between them.
If you take medication, are pregnant, or have a health condition, check with a pharmacist or GP first.
Source: The Food Supplements (England) Regulations 2003, regulation 6(2)(c) (checked 22 September 2026)
Why do labels say a supplement is "not a substitute for a varied diet"?
Because UK law requires this exact statement, in substance, on every food supplement label.
Labels must state that “food supplements should not be used as a substitute for a varied diet”, one of the fixed pieces of required wording alongside the recommended daily portion and the dosage warning, coming from the Food Supplements (England) Regulations 2003, regulation 6(2)(d) (equivalent rules apply across the UK). This reflects the legal definition of a supplement as something that adds to an ordinary diet, not something that replaces it, and appears on every product regardless of the ingredient.
If you take medication, are pregnant, or have a health condition, check with a pharmacist or GP first.
Source: The Food Supplements (England) Regulations 2003, regulation 6(2)(d) (checked 22 September 2026)
Who is advised to check with a pharmacist or GP before taking supplements?
People who are pregnant or breastfeeding, people taking prescribed medication, and people with an existing health condition are the groups most consistently advised to seek medical advice before starting a supplement.
A supplement can interact with a medicine or a condition in ways a label cannot account for. NHS guidance on pregnancy, for example, directs a higher folic acid dose to people with specific conditions or medicines, adding “talk to your midwife or GP if you have any questions” (NHS: Pregnancy vitamins and supplements, checked 22 September 2026). This is why every Class B answer on this site, and this one in particular, ends with the same fixed line below.
If you take medication, are pregnant, or have a health condition, check with a pharmacist or GP first.
Source: NHS: Pregnancy vitamins and supplements (checked 22 September 2026)