What is the difference between natural progesterone and synthetic progestins?

This is one of the most important distinctions to understand when considering hormone therapy. Natural progesterone is molecularly identical to the hormone your body produces. It fits your body's receptors perfectly and is used by the body in exactly the same way as its own hormone — with no known toxic side effects.

Synthetic progestins and progestogens, on the other hand, have an artificially altered molecular structure. They were created because natural progesterone cannot be patented — so pharmaceutical companies modify the molecule to make it patentable.

While progestins can mimic one function of natural progesterone (maintaining the uterine lining), they behave very differently in the body in every other respect.

Known side effects of synthetic progestins include fluid retention, depression, nausea, insomnia, breast tenderness, migraines, increased cancer risk, and a drop in the body's own progesterone levels — among others.

As Dr. John R. Lee noted: "The addition or subtraction of a few atoms of a molecule can make a big difference in their effects on the body. Tiny amounts can create major effects."

The only similarity between progestins and natural progesterone is their ability to maintain the endometrium. In every other way, they are fundamentally different substances.

Natpro contains only natural, bioidentical progesterone — not synthetic progestins.