Home remedies · Everyday life & travel
No home remedy here replaces treatment, and none is talked down. What has done good for generations does good — even if no one ever measured it. Where something is well studied, it says so. Where it is only experience, it says that too.
Stir half a teaspoon of baking soda into a little water to make a thin paste and apply it after showering to the dry armpit; let it dry on. Or dry: spread a knife tip of it thinly with a cotton pad. Once a day is enough.
Sweat itself does not smell. The smell is made by skin bacteria, above all corynebacteria, which break the components of underarm sweat down into short-chain fatty acids and sulphur compounds. Those bacteria work best in the slightly acid range where skin normally sits. Baking soda is alkaline; it lifts the pH of the skin surface for a few hours and so slows the breakdown. It is not an antiperspirant — it does not stop the sweat, but what becomes of it.
Precisely because it shifts the pH it irritates sensitive skin: redness, burning and flaking after a few days are the commonest reason for dropping it again. Not on freshly shaved skin and not on broken skin. Anyone who tolerates it gets by with little; more does not work longer, it only irritates sooner.
If the smell changes markedly or turns sweetish, with heavy sweating for no reason and at night, with weight loss, and when wet armpits govern the day — there are stronger means than baking soda for that.
Have it assessed: heat with confusion, dry hot skin or clouded consciousness — that is more than exhaustion. A one-sided swollen leg after a long journey. And anything new that does not go away within a few days.