Yes. Active filters break down. The FDA requires OTC sunscreens to stay at labeled strength for at least three years from manufacture when stored as directed. A tube that spent July in a car trunk can fail earlier than the stamp.

Using a dead bottle is worse than skipping it: you behave as if you are covered. Check the date before a beach week, not after the burn.

Read the stamp, then look at the cream

Most U.S. bottles print an expiration date. No date? Write the purchase month on the cap and throw it out at three years. Toss it sooner if it has separated, gone grainy, or smells off.

If you actually use the recommended ounce per full-body coat, a family bottle empties in weeks. Expiration is mostly a leftover-from-last-summer problem.

Heat is harder on it than the calendar

Chemical filters such as avobenzone fade faster in heat and light. Mineral zinc and titanium hold up better in a closet, but both classes expire, and neither likes a glove box. Room temperature, cap closed, out of direct sun.

Related: how long a coat lasts on skin is a different clock from how long the bottle lasts on a shelf.