There are two hormones in Lutera. They’re pretty much the same as progesterone and estrogen. You have these hormones naturally in your body, and they fluctuate over the course of your menstrual cycle. When they rise and fall, they tell your body to do different things like ovulate and shed your womb lining (that’s when your period happens).
The way the pill works is by supplementing hormone levels in the body. This tricks your body into thinking that ovulation has already happened. The ovaries don’t release an egg, and fertilization can’t take place.
These hormones also stop the lining inside the womb from getting thicker, making it less likely that an egg would be able to implant itself there, assuming it somehow got fertilized. For some women, this has the added benefit of making periods lighter.