The entire purpose of self tanners is to "stain" your skin. Most contain dihydroxyacetone (DHA), a color additive, that colors your skin. That same additive can stain - sometimes permanently - your clothes if it touches them when in a wet form.
Self tanning formulas are a combination stain of dye and oil. Combination stains like ballpoint ink, crayon, gravy and makeup contain both an oily/waxy component and a dye/pigment component. Start by removing the oily portion first and then tackle the dye stain. Take your time and most will come out with some effort.
For washable fabrics, first flush any stains as quickly as possible with cold water. Hold the stain (wrong side) under a running stream of cold water. This will force the self-tanner out of the fabric instead of pushing it deeper into the fabric by rubbing.
Mix a solution of dish detergent and warm water and sponge the stain - working from the outside of the stain to the inside. Gently rub the soapy solution into the stain. Rinse.
If the stain remains and the garment is light colored, use hydrogen peroxide (3 percent solution) on a white cloth to dab it on the stain. If you are not sure if the garment is colorfast, test the hydrogen peroxide on an interior seam. If there is transfer of color to your white cloth, do not use. Rinse after treating with hydrogen peroxide.
If the stain remains, try rubbing glycerin into the stain. The glycerin can help break down the stain. Repeat the dish detergent and peroxide steps.
Do not place the garment in a dryer or hang in the sun until all stains are removed. High heat can permanently set the stains.
If the garment is dry clean only, point out and identify the stain to your professional cleaner. If you are using a home dry cleaning kit, be sure to treat the stain with the provided stain remover before putting the garment in the dryer bag.
TIP: Don't wear nylon or light-colored clothing within 12 hours of applying self-tanner.
