During my 3 pregnancies, I did have that glow on my face like some women would have. Though I was still slim except for the belly, my face had acne outbreak during the first trimester. I dared not apply OTC pimple cream like Oxy 5 on my face and only relied on toothpaste to treat the pimples. I dabbed a small dollop on the pimples and within 2 days, the pimples would dry up. The down side of using toothpaste is that it will make your skin sting and dry up your skin, making it red and ‘withered’. Nonetheless, I still used toothpaste as it’s safer than using OTC pimple creams with potent ingredients in them. I figured that if it’s safe to put into your mouth, it’s safe for your skin too.

I read that you can also use tea tree oil or apple cider vinegar (ACV) instead as they won’t dry the pimple out as much.

If you want to use toothpaste to get rid of pimples, look for a true toothpaste, not a gel, and if you can, find one with minimal additives. Natural or organic toothpastes are a good bet, since they usually have a short ingredient list. Apply a small dab to the acne spot in question, leave it on overnight, and rinse in the morning.

Avoid popping pimples, no matter how tempting it is (sometimes I can’t resist popping them too!), because you can actually make the situation worse by causing a deep infection with your fingers that may have germs.

Here’s an article on treating acne with toothpaste from acne.about.com :

Toothpaste is often thought of as an inexpensive spot treatment for pimples, but this is one home remedy you don’t want to try. Although some swear toothpaste dries up their pimples quickly, most people will find the toothpaste leaves their skin red and irritated.

The idea to use toothpaste as a spot treatment is probably due to the fact that many types of toothpaste contains triclosan. Triclosan is an antibacterial ingredient often added to personal care items like soap, deodorant, and body wash. Triclosan effectively kills bacteria. It is actually a common addition in acne treatment products, although as a preservative and not an active ingredient.

But toothpaste also contains ingredients that can irritate the skin, especially the delicate skin on the face. Using toothpaste on an already inflamed pimple can cause more redness and irritation. Many unfortunate souls say toothpaste burns really badly when applied to a zit, and leaves the skin feeling sore for days afterward. Bottom line: Toothpaste can make your pimple look worse instead of better.