Bioadhesive Gel (Crinone)
Crinone gel is also applied vaginally. In contrast to suppositories, however, the progesterone is suspended in a bioadhesive gel (sold without progesterone under the brand name Replens) and is packaged in a tampon-like applicator. Crinone gel is highly efficient at the uterine level; in fact, the progesterone stays so concentrated in the uterus that Crinone often has minimal impact on serum progesterone levels. Crinone is frequently used as a progesterone supplement in IUI and IVF cycles.
This uterine level impact is one of the primary advantages of Crinone, as is the fact that many patients only need to apply it once a day. For many women, Crinone is far better at delaying premature onset of menstruation than are suppositories or oral progesterone. Some women do, however, find that the suspension gel accumulates in the vagina and may need to be removed every couple of days; additionally, patients occasionally experience vaginal irritation as a result of the build-up.