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📅 Practical tool  ·  30+ supplement types

Supplement Expiry & Potency Calculator

Is your old supplement still worth taking? Enter the supplement type, purchase date, and how you've been storing it — get an estimated remaining potency and practical advice.

Storage Rules That Save Your Supplements

✓ Refrigerate these

Probiotics (most strains), fish oil (prevents oxidation), certain protein powders, liquid supplements, and opened collagen powder. Check label.

✕ Never store here

Bathroom cabinet (humidity and heat degrade most supplements). Kitchen countertop (heat from stove). Car glovebox (extreme temperature swings).

⚠ Fish oil rancidity check

If it smells strongly fishy or rancid — discard. Oxidised omega-3 is counterproductive. Refrigerate after opening. Enteric-coated capsules last longer.

ℹ Vitamin C degrades fastest

Ascorbic acid is highly sensitive to heat, light, and moisture. Buffered forms (sodium/calcium ascorbate) are more stable. Check for yellowing or clumping — both indicate degradation.

Are expired supplements dangerous?
Most expired supplements are not dangerous — they simply lose potency over time. The main exceptions: fish oil (can turn rancid and produce harmful oxidation products if stored poorly), fat-soluble vitamins (A, D, E, K) in very old supplements (possible degradation products), and probiotics (lose viability, not dangerous but ineffective). If a supplement smells unusual, has changed colour, or shows visible degradation, discard it. Otherwise, an expired supplement is more "less effective" than "harmful."
Does creatine expire?
Creatine monohydrate is exceptionally stable when stored dry. Sealed, in a cool dry location, it retains full potency for 2–4 years beyond the manufacture date. Once opened and exposed to moisture, it can hydrolyse to creatinine (the waste product) more quickly — keep it sealed and dry. If it's clumped, there's been moisture exposure but it's typically still effective at reduced potency.
How long do probiotics last?
Probiotic viability drops significantly with temperature and time. Refrigerated probiotics stored correctly retain 70–80% viability for 6–12 months. Room temperature "shelf-stable" probiotics use lyophilisation and heat-resistant strains — viable for 12–18 months if stored cool and dry. After expiry, CFU count may be well below label claim. For therapeutic use (antibiotic protection), use fresh, in-date probiotics.