The Truth About Expiration Dates

Most supplement bottles have a “best before” stamp – but what does it really mean? We uncover how stability testing works and whether expired supplements are still safe.

You’ve probably noticed the small “EXP” or “Best Before” stamp on every supplement bottle. But how much should you actually trust it? And what happens once that date has passed?

What Expiration Dates Really Indicate

Supplement expiration dates are not the same as food spoilage warnings. Instead, they’re based onstability testing— controlled studies that measure how long the active ingredients remain potent under specific storage conditions. Most brands test products for anywhere between 12 and 36 months, and the printed date reflects the point at which the manufacturer can guarantee full potency, not when the supplement suddenly becomes harmful.

Potency vs. Safety

The key distinction: expired supplements usually aren’t unsafe, but they may be less effective. For example, vitamin C can oxidise and lose strength over time, while probiotics may see a sharp drop in live cultures. Minerals like magnesium or zinc, however, are far more stable and tend to remain intact for years.

Why It Matters

If you’re taking supplements for general wellness, taking one past its expiration date may not be a major issue — you just might not get the full advertised benefit. But if you rely on a precise dosage (such as vitamin D for deficiency correction), expired products could mean you’re not getting what you need.

How to Store for Maximum Shelf Life

• Keep bottles sealed tightly and away from moisture.
• Store in a cool, dark place — heat and light accelerate breakdown.
• Avoid transferring capsules or powders into unlabelled containers.

Bottom Line

Expiration dates on supplements are less about danger and more about guaranteed potency. With proper storage, many remain stable well beyond the printed date, but the effectiveness is never assured. When in doubt, replace critical supplements and treat dates as a guide, not an absolute cutoff.