TL;DR
A makeup bag is a warm, closed pouch holding pigment, oil, and everything your hands have touched, and most people clean it roughly never. Empty it completely, shake out the loose powder, pretreat greasy stains with dish soap, then wash by material -- fabric by hand or in a mesh bag, vinyl and leather wiped only. Dry it inside out and completely before you refill it.
What is actually in the bottom of the bag
Empty one out and you find a fine gray dust made of pressed powder, eyeshadow fallout, and loose pigment, bound together by foundation, primer, and skin oil that has leaked out of caps.
Add hair, dust, and whatever the bag picked up from a bathroom counter or the bottom of a purse, and there is a lot going on in there.
That mixture matters because it gets back onto brushes, sponges, and product packaging every time you reach in. Cleaning brushes carefully and then putting them back in a dirty pouch undoes half the work -- see how to clean makeup brushes without ruining them.
Damp items make it worse. A sponge that goes in still wet turns the inside of the bag into a humid box, which is exactly the environment described in how to clean a makeup sponge properly.
How do you clean a makeup bag?
Empty it completely, turn it inside out and shake out the loose powder, then vacuum or wipe out the residue. Pretreat greasy stains with a drop of dish soap, hand wash fabric bags in warm soapy water or machine wash sturdy ones in a mesh bag, and air dry inside out.
Step one, empty and dry clean it
Take everything out. Everything. This is also the moment to check expiry dates and throw out anything separated, dried, or smelling wrong.
Turn the bag inside out if it will. Shake it out over a bin or outdoors.
Vacuum the interior. A crevice tool or a handheld vacuum pulls loose powder out of seams far better than shaking. This alone transforms most bags.
Wipe the interior with a dry cloth or a lint roller. Do this before anything wet, because water turns loose pigment into a spreading stain.
Check the seams and corners. That is where compacted powder collects.
For a bag that is only dusty, this is the whole job. Not everything needs a wash.
Step two, treat the stains before washing
Foundation, concealer, and cream products are oil-based, and water alone will not shift them.
Put a small drop of dish soap directly on the stain and work it in gently with a fingertip or a soft brush. Dish soap is formulated to cut grease, which is exactly what this is.
Let it sit five to ten minutes, then rinse or blot with warm water.
For lipstick and cream blush, the same approach usually works. For something stubborn on a washable fabric bag, a laundry stain remover applied per its own instructions is the next step.
Test any product on an inside seam first, especially on colored or printed fabric.
Do not use bleach. It will strip color from the bag, and it should never be mixed with any other cleaner in any case -- combining bleach with an acid or with ammonia releases toxic gases.
Washing by material
Cotton, canvas, and polyester. Hand wash in warm water with a little detergent or dish soap, scrubbing the interior with a soft brush. Or machine wash in a mesh laundry bag on a gentle warm cycle. Air dry inside out.
Nylon and coated nylon. Hand wash, since machine agitation can damage the coating. Wipe the interior with a soapy cloth, rinse, and air dry.
Vinyl, PVC, and clear plastic. Do not machine wash. Wipe inside and out with a cloth and warm soapy water, rinse with a clean damp cloth, and dry immediately. Heat makes vinyl brittle and cracks it.
Leather and suede. Wipe only. A barely damp cloth for leather, dried straight away, and a suede brush for suede. Never soak either. A leather conditioner occasionally keeps it from drying out. Water leaves permanent marks on suede.
Mesh and clear zip pouches. Usually the easiest. Warm soapy water, a soft brush, rinse, air dry.
Bags with a removable lining. Take it out and wash it separately if it is designed to come out.
Never put a makeup bag in a dryer. Heat warps zippers, shrinks linings, and cracks coated fabrics. Air dry inside out, over a rack or a hook, until completely dry.
Why does my makeup bag smell?
A closed bag holding damp sponges, leaking product, and skin oil grows bacteria and mildew, and old cosmetics develop their own odor as they oxidize. Wash the bag properly, discard anything past its date, and never store a damp sponge or brush inside it.
Keeping it clean between washes
Wipe the inside with a damp cloth once a week. It takes a minute and prevents almost all buildup.
Wipe product packaging before it goes back in. Foundation bottles and lipstick tubes are usually the source of the mess.
Never store a wet brush or sponge in a closed bag. Let them dry fully in open air first.
Use small pouches inside a bigger bag to separate wet-prone items, brushes, and powders. Contamination is much easier to contain than to remove.
Do not set a makeup bag on a public bathroom counter or a restaurant floor and then on a bed at home. That is how a bag becomes a transport system.
Keep it out of a hot car. Heat degrades cosmetics, causes leaks, and can crack vinyl.
Store it somewhere dry rather than in a steamy bathroom, the same reasoning behind how to clean an acrylic cosmetic organizer and running through cleaning the personal items you use every day.
Source: U.S. Food and Drug Administration consumer information on cosmetic safety and storage
How often, and when to replace it
Wipe weekly, wash monthly for a bag in daily use. A travel bag can be washed after each trip.
Wash it immediately after a spill, after a trip, or if anyone in the house has been sick.
Replace the bag when the lining is stained beyond cleaning, when the zipper fails, when the coating is peeling or cracking, or when a smell survives a proper wash. Peeling vinyl sheds flakes into everything inside.
A bag that has held a leaking liquid product for a long time often keeps the odor no matter what you do. That is a replacement.
FAQ
Can you put a makeup bag in the washing machine?
Sturdy cotton, canvas, and polyester bags can go in a mesh laundry bag on a gentle warm cycle. Do not machine wash vinyl, PVC, leather, suede, or anything with beading, glued decoration, or a stiff structured shape. Never put any makeup bag in a dryer.
How do you get foundation stains out of a makeup bag?
Apply a small drop of dish soap directly to the stain and work it in with a fingertip or soft brush, since foundation is oil-based and dish soap is made to cut grease. Let it sit five to ten minutes, then rinse or blot with warm water and wash the bag as usual.
How often should you clean a makeup bag?
Wipe the inside with a damp cloth weekly and give it a proper wash monthly if you use it daily. Wash it right away after a spill, after travel, or if someone in the household has been ill. A travel bag is easiest to wash after each trip.
How do you clean a vinyl or clear plastic makeup bag?
Wipe the inside and outside with a cloth and warm soapy water, rinse with a clean damp cloth, and dry immediately with a towel. Do not machine wash or use hot water, since heat makes vinyl brittle and cracks it. Avoid alcohol, which can cloud clear plastic.
Can you clean a leather makeup bag?
Only by wiping. Use a barely damp cloth on the outside and dry it immediately, then apply a leather conditioner occasionally to keep it from drying out. Never soak leather or machine wash it. Suede needs a suede brush and no water at all, since water leaves permanent marks.
Why does my makeup bag smell bad?
Usually because damp brushes or sponges have been stored inside, or a product has leaked and sat. A closed pouch holding moisture and oil grows bacteria and mildew. Wash the bag, discard expired cosmetics, and let anything wet dry completely in open air before it goes back in.
Small routines like this are quick. Keeping a whole bathroom or bedroom clean is not. If you would rather hand that off, get a quote or read more about house cleaning services.