Bras need to be washed more often than you think. Ideally, a bra shouldn’t be worn two days in a row, and it should be washed between each wear. Why? As a bra is worn, sweat and dead skin cells become embedded in the fabric and elastic.
The longer a bra is worn without being cleaned, the more sweat and dirt will build up on the fabric, making it more difficult to get clean. Over time this wears away at the bra, decreasing its lifespan.
Do Not Use Detergent
Your bra will last the longest if you clean it using gentle lingerie wash, as detergent harms undergarment elasticity. If a proper wash is not available, a mild, non-biological detergent or mild baby shampoo will do the least harm. In addition, always avoid fabric softener on bras.
Hand Washing Gets the Job Done
The preferred way to clean a bra is washing by hand, because it is the gentlest. It makes lingerie last the longest, being the safest on shape, elasticity and color.
To begin, fill a large basin or sink with lukewarm water and add a small amount of lingerie wash. Then, add the bra to the soapy water. After making sure that it is submerged, let it soak for a several minutes.
After soaking, gently pump the bra up and down in the water a few times to loosen dirt. To remove spots, gently rub them. Pay special attention to the underwire, straps, and the portions of the panel near the armpits, as these locations accumulate the most sweat and body soil. Spend a few minutes doing this, and then empty the sink of dirty water.
Refill the sink with clean, room-temperature water, while rinsing the bra in the running water. After pumping the bra in the sitting water once more to rinse away any residual lingerie wash, fully remove it from the basin.
Avoid the Tumble Dryer at All Costs
Do not put bras in a tumble dryer – the heat will destroy its elasticity quickly! Rather, a bra will best keep its elasticity and shape if laid out to dry.
Spread a towel on a solid surface. Lay the bra entirely flat on the towel, trying to keep the straps and panels loose and unwrinkled. If you are working with a molded cup bra, gently reshape the cups, but do not wring out the water. After letting the bra fully dry, make sure to shape the cups before placing it in a drawer. Then, your bra will be ready, waiting for its next appearance.
References
https://www.goodhousekeeping.com/beauty/fashion/how-to-buy-a-bra#slide-5
https://www.investinyourchest.co.uk/how-to-hand-wash-your-bras
https://www.herroom.com/know-your-breasts/lingerie-washing-guidelines,306,30.html
https://thelingerieaddict.com/2009/08/how-often-should-you-wash-your-bra.html
https://bustyresources.wikia.com/wiki/How-to_wash_a_bra
Breaking it down, Hayley.