Generally, glycolic acid products will last for nine months to a year. It is always better to get a tight-pumped or a vacuum-sealed container to make the product last longer. ... However, using a product past its expiration date, like glycolic acid, may cause it to be less effective on your skin.

How long does glycolic acid last?

Anti-aging products with ingredients like retinol, glycolic acid and vitamin C can break down quickly and typically last nine months to one year, depending on how they're dispensed. Opt for vacuum-sealed products in air-tight pump bottles for a longer lasting product.

Why you shouldn't use glycolic acid?

Depending on the concentration (and not unbeknownst to chemical peel-havers) it can cause flaking and scabbing straight after application. It also makes you more prone to sun damage, so if you forget your SPF you're pretty screwed and could get very burnt (as well as all the other bad stuff that comes from sun damage).