Progesterone In Your Pill: If the shoe fits, wear it!
Posted Jun 21 2010 7:16pm
So, what makes one combination oral contraceptive pill (OCP) different from another? What’s the difference between brand-name and generic versions, if any?
The answer generally boils down to one word: progesterone. How do we know this? Because the chemical composition of the estrogen component of almost every OCP marketed in the U.S. is exactly the same. It’s ethinyl estradiol. The only thing that changes from pill-to-pill is the dose (thus the idea of “low dose” pills, “triphasic” pills etc), as described in my previous post .
So, although all “low dose” OCP’s may contain 20 micrograms of estrogen, there are dozens of different kinds because each manufacturer uses one of eight different kinds of progesterone in each type of pill.
The type of progesterone is indicated by the second word in the pill’s generic name. For example, Loestrin is ethinyl estradiol and NORETHINDRONE. Other pills have other progesterone components (i.e. Ortho-Tri-Cyclen and Ortho-Tri-Cyclen-Lo contain NORGESTIMATE, Yasmin andYaz contain DROSPERINONE). You get the idea.
So, why do we need so much variety? Can’t everyone just use the same pill in different doses? Like Advil or Tylenol, just use a higher dose if you need more of it?
Well, it’ s not that simple. The dose isn’t the important thing (it’s usually low, about 1-2 mg). It’s the differences in the chemical characteristics of the progesterone that make each pill unique and separate it from its similar contraceptive cousins.
Some progesterones have a higher level of “progestational activity .” This means the degree to which it binds with progesterone receptors in the body. In addition to preventing pregnancy, stronger progestational agents can lessen menstrual bleeding, reduce acne, lessen excessive hair growth, etc.
Some progesterones have an effect on blood levels of potassium or cholesterol. Some can increase a person’s risk of blood clots. These risks and benefits are an important topic to discuss with your gynecologist (or other prescriber).
As if things weren’t confusing enough, generic OCP’s have active ingredients (estrogen and progesterones) which are chemically identical to the brand-name version. They are, however, made by different manufacturers. They may contain different additives or be formulated in a slightly different way.
That’s why some people find that, while the brand name version worked well for them, different symptoms occur when they switch to the generic version(or vice-versa). This means you may need to pay more (or less) for the version you prefer. The cost difference can be significant ($50 or more!), so consider the choice carefully.
It’s often difficult to predict which oral contraceptive (and which progesterone) will work best with a particular person’s chemistry. While your gynecologist (or other provider) can often guide you toward picking an oral contraceptive which is the most likely to satisfy your partiuclar needs, sometimes, it’s necessary to try out a few different types before you hit on a pill that you like.
But when you do… Wow. It’s like Cinderella fitting perfectly into that glass slipper and living happily ever after. And not getting pregnant on that pumpkin-carriage ride home.