Millions of us are taking supplements every day to help support a range of health functions. But how many of us are swallowing out-of-date vitamins and minerals or capsules that are no longer effective? We’re way more conscious of food sell-by dates than we are of supplements. But the truth is, when it comes to lifespan, not all liquids, powders, gummies and pills are made equal.

“The shelf life of supplements depends on the type of supplement taken, how they are stored and whether or not they contain perishable ingredients,” explains Dr Emanuel Paleco, a biologist and medical physicist. “Most supplements are good for between one to three years from the time they were produced, but effectiveness may be reduced.” He notes, for example, that probiotics, fish oil and other liquid vitamins are best used within two years and require refrigeration to preserve their effectiveness.

Other supplements, however, might last longer – even beyond their ‘best before’ dates. “Once supplements pass their ‘best before’ date, they might gradually lose potency, meaning they may not be as effective as they were originally intended. However, most supplements remain safe to consume after this date, provided they have been stored properly,” says Dr Rayyan Zafar, a scientist at Imperial College London and the chief scientific officer at Moodeys.

Dr Zafar points to a study that suggested 90% of more than 100 drugs – prescription, over-the-counter and dietary supplements – were OK to use up to 15 years after the expiration date. 

The expiration date marks the final day a manufacturer guarantees the complete safety and potency of the product, so while such research is reassuring and may prevent large quantities of medication from being wasted, when it comes to certain supplements, there are other things we need to consider.

Which supplements last the longest?

“Solid forms, such as tablets and capsules, are the most stable past their expiration date. Supplements that exist in solution or as a reconstituted suspension (powder mixed with water) are less likely to be potent if used when outdated,” explains Dr Zafar.

Registered nutritionist and Nutritionist Resource member Amie Parry-Jones says: “Oils such as fish oil and flaxseed oil benefit from refrigeration to slow oxidation. While they may last for a few years unopened, it’s important to remember that once a seal is broken on some products, they don’t last more than a few weeks. For this reason, capsules containing oils are a more practical solution for people.

“This is also the case with freshly ground flaxseed. Once the seeds are broken down and the oils within are exposed to environmental influences, they can go rancid quite quickly.”

Parry-Jones also notes that even if a supplement remains safe to ingest after its ‘best before’ date, it could be indirectly harmful. “For example, if you’re taking B12 for a deficiency, an expired supplement – depending on how old it is – won’t be likely to increase B12 levels as effectively, which impacts symptom alleviation. Another important example is folic acid in pregnancy supplements,” she explains.

Dr Paleco advises: “Check your supplements from time to time to see if there is any change in the colour, smell or feel of the supplements, as this may indicate that the supplements are already spoiling.” 

What is the best way to store supplements?

One of the reasons your supplements may prematurely degrade is due to the storage method. “High temperatures can break down vitamins like vitamin C and B-complex, while moisture causes clumping or degradation of capsules and powders,” says Amie Alexander, a registered dietitian at Nutri Peak. “People often keep their supplements in the kitchen or bathroom, but these are areas subject to high humidity and fluctuating temperatures, which could speed degradation among sensitive compounds.”

Dr Zafar advises storing supplements in a cool, dry place away from direct sunlight and heat sources – typically at temperatures between 15–25°C. If you prefer to transfer your supplements from the original packaging into other containers, Dr Zafar says that’s fine, but such containers “should be airtight, opaque to block light and properly labelled with the original expiry date”. However, keeping them in their original containers might be the best option to retain optimum storage conditions. 

Parry-Jones also highlights the importance of checking whether a supplement requires refrigeration. “Most shop-bought probiotics are fine kept at room temperature, but some require refrigeration to optimise potency and extend shelf-life as probiotics are living organisms,” she explains. “This depends on the strains of probiotics in the supplement as some are more resilient to temperature fluctuations. The manufacturer will include the appropriate instructions and even offer cold-storage delivery if necessary.”

Fridge placement also matters for liquid supplements (including ground flaxseed). “Avoid keeping them in the fridge door, which is prone to temperature fluctuations as the fridge is opened and closed,” advises Parry-Jones.

Another significant yet overlooked aspect, says Alexander, is potential cross-contamination when handling your supplement. “I always advise that when withdrawing capsules or powders, you’re better off using dry, clean hands or a spoon, since oils or moisture provided by skin might introduce bacteria contamination or lead to premature breakdown of the capsule or powder,” she says.

Four tips for storing supplements (and elongating their shelf life)

Images: Getty