Is there a difference between the hormones progesterone and progestin?

This is a frequently asked question regarding progesterone. Nest Guzman, Pharmacy Student from the Class of 2015 just completed a clinical rotation at our pharmacy and offers this information on the topic:

Progesterone is a natural hormone produced by the adrenal gland and the ovaries in women, and the testes in men. It has effects in various parts of the body including the endometrium, breast, brain, bones, and blood vessels. Progesterone is an integral part of the hormone balance and serves as a precursor hormone to other hormones such as cortisol, aldosterone, estrogen, and testosterone. When there is a progesterone hormone deficiency two hormone replacement treatment options are available, progesterone or progestin. The differences that distinguish progesterone from progestin are their structure, their benefits, and their side effects.

One difference is that progesterone is bio-identical, an exact natural structural copy to the body’s hormone. Therefore, progesterone will have a perfect fit with all available body’s progesterone receptors, and produce the desired effect. This is important because body receptors are structure specific. Progestin on the other hand is a synthetic analog or look-alike that closely resembles progesterone structure. It will potentially act on progesterone receptors as well as other body receptors, producing desired and undesired effects. Some known progestins are Depo-Provera (medroxyprogesterone) injection, and oral Micronor®, Nor-QD® (norethindrone).
Progesterone and progestin have different benefits and side effects. Some of the natural progesterone benefits are embryo survival and development, possible protection against breast cancer and endometrial growth, increase in bone building, normalizing blood clotting, restoring libido, and acting as a natural antidepressant. Side effects are fatigue and somnolence. Progestin’s benefit, such as Depo-Provera®, is protection against endometrial growth. Progestin’s side effects are risk of early abortion, increased risk of breast cancer, increased risk of osteoporosis, increased blood clotting, weight-gain, decreased libido, possible depression, migraine headaches, among others.

If we have a progesterone deficiency and are in need for hormone replacement treatment, it appears that the better hormone replacement option is the one that is natural bio-identical, one that is structurally identical to the body’s hormone. This is important for an exact fit and the least side effects. Natural progesterone is the hormone treatment that best meets these criteria.

References:
1. http://www.project-aware.org/Resource/articlearchives/differences.shtml. Accessed November 11, 2014.
2. http://womeninbalance.org/resources-research/bioidentical-progesterone-vs-synthetic-progestins/. Accessed November 13,2014.
3. http://www.aafp.org/afp/2000/1015/p1839.html. Accessed November 14/2014.4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1974841/?report=reader#!po=9.15493. Accessed November 15, 2014.

“These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.”

Hoye’s Pharmacy is a compounding pharmacy located in Florida.