Can you use lotion as lube?

No. Lotion is built for the skin on your arms, not for mucous membranes. Its fragrance, preservatives, alcohol and emulsifiers irritate genital tissue, and many lotions carry mineral oil or other oils that break latex condoms. Irritation and a yeast or bacterial vaginosis flare are the common outcomes.

What is in lotion.

Lotion is an emulsion: water and oil held together by emulsifiers so it does not separate in the bottle. On top of that base sit preservatives to keep it from growing mold, fragrance to make it pleasant, often alcohol to make it feel light, and sometimes glycerin, retinol, acids, menthol or sunscreen depending on what the front of the bottle promises. Every one of those ingredients was chosen and tested for skin. None was tested for the inside of a vagina or the surface of a penis.

Why skin tolerates it and mucous membranes do not.

Skin has a dead outer layer of keratin that acts as a barrier. Mucous membranes do not. They are thin, wet, absorbent and full of nerve endings, which is why they are sensitive in the first place. An ingredient that produces no reaction on a forearm can sting, itch and inflame genital tissue, sometimes on the first contact and more often after repeated use. Fragrance and alcohol are the usual culprits, with preservatives close behind.

The vagina also runs acidic, with a healthy pH of 3.8 to 4.5, and depends on that acidity to keep its bacteria in balance. Lotion is not formulated for that range. Disrupt the balance often enough and yeast or bacterial vaginosis follows.

The condom problem.

Most lotions contain mineral oil, petrolatum, shea butter, coconut oil or another oil. All of them weaken latex and polyisoprene condoms; the WHO/UNFPA/FHI360 advisory lists oils and petroleum products as having a highly damaging effect on latex. Because you cannot tell from the front of the bottle which oil a lotion uses, treat every lotion as not condom safe.

What happens if you use it.

Often, nothing the first time, which is how people come to do it regularly. Over repeated use the pattern is burning during or after, itching the next day, a change in discharge or smell, and eventually a yeast infection or bacterial vaginosis that keeps coming back and gets blamed on everything but the lotion. For men, the equivalent is redness and soreness on the penis, sometimes with small cracks in the skin.

"Unscented" lotion is not the fix. Unscented often means a masking fragrance was added to cover the smell of the base, and all the other ingredients are still there.

On the outer skin, briefly, with no condom involved, most people have no problem. Anything internal, anything with a condom, or anything regular calls for real lube.

What to use instead.

A bottle of lube costs about what a bottle of lotion does and is built for the tissue in question. Two that are glycerin free, fragrance free and inside the WHO ideal osmolality band of 380 mOsm/kg or under: Good Clean Love Almost Naked, which measures 240 to 269 mOsm/kg with a pH of 4.7, and Astroglide Ultra Gentle Gel, which measures 200 to 300 with a pH of 3.5 to 5.5 and is sold at most drugstores. Both work with every condom and every toy.

If lotion has already caused burning, itching or a change in discharge that lasts more than a few days, see a clinician. Nothing here is medical advice.