Why are my bra straps always slipping off?

Bra straps slip off your shoulders due to several key design and fit factors that affect how garments interact with your body. 

Strap slippage commonly occurs when your bra or garment lacks proper support structure, with ill-fitting bands that are too loose or straps positioned too wide for your shoulder width. The natural shape of your shoulders may also contribute, as narrower or more sloped shoulders require garments specifically engineered to provide secure positioning.

Over time, wear and washing can cause straps to lose their elasticity and original shape, especially when delicate items aren't properly protected during laundering.