In short, no.
Our skin has very different needs that our body’s nutritional needs.
Think of your skin as a dog; you wouldn’t get a dog and only feed it things you ate. Sure, that would work out fine in many cases (meat, sweet potatoes, water), but it’d prove lethal in others (chocolate, grapes, garlic, onions). Dogs have different dietary needs—and bodies—than humans do, so you cannot assume something is safe for a dog because it’s safe for a human.
The same goes for the skin.
Many ingredients that are perfectly safe for use on the skin would make you very sick or ill if you ingested them. This is not an indicator that the ingredient is unsafe; it just means you shouldn’t eat it.
Would you sit on a toilet seat, but not lick it? Same deal.
One of the best examples of a type of ingredient that is safe when used in skincare at responsible levels but can make you very sick if ingested is essential oils. It depends on the essential oil, of course, but experts do not recommend consuming essential oils unless under the supervision of a qualified professional.
There are also plenty of things that are safe to eat, but detrimental to skin health. Examples include lemon juice, hot sauce, and baking soda. These ingredients will disrupt your skin’s natural barrier and can lead to burns, rashes, and irritation.
The skin is an excellent barrier. It has evolved to protect us from the outer world and keep our internal organs from falling onto the sidewalk. The notion that your skin absorbs everything you put on it as if you were eating it is flat out wrong. If that was true, you would need to buy new underpants all the time because they would constantly be absorbed into your bloodstream. You’d also need pee ferociously shortly after getting into the bath, or overdose on sodium every time you swam in the ocean. You do not need to worry about your body absorbing all of your skin care products through it.
Posted in: Safety