Aren't we going to tell you that you should get a prescription from your doctor and skip the OTC stuff? No. We happen to feel that prescription progesterone creams are more accurately prepared, fresher, better handled, and less expensive. But we also know that this isn't an ideal world where our doctors are completely in harmony with our own assessment of our needs, and sometimes we work with suboptimal conditions. A woman does what she feels she must, and we have to respect her right to do so, although we also hope that she'll fully educate herself about progesterone risks as part of her decision process. All we can hope to do is make you a little smarter about whatever it is that you decide is the best course for your own body.
How to tell if it has real progesterone in it
We can hope that the cream we buy is powerful due to containing a hormone. Many so-called progesterone creams do not contain effective ingredients. In particular, creams that contain "wild yam extracts" or "Mexican yam" or "diosgenin" as their only active ingredient are not going to provide progesterone. While it is true that progesterone is produced in the lab from this plant source or partially-refined source, these sources cannot be converted to progesterone in the body. Creams containing these ingredients may cause produce some degree of effect when used, but that effect is not due to progesterone.
We have to be careful to read the ingredients, not just the label and advertising, though: some things that are called "Wild yam" actually contain real progesterone and some things called progesterone only contain wild yam. What a cream must contain to be effective is "USP Progesterone," and unless the label specifies this as an ingredient, we're not getting it.
We'll find OTC creams available in various strengths, but in practical terms, the ones that contain about 450 mg/oz are the only ones worth purchasing. Others that contain lesser amounts require such a large volume of cream to deliver an effective dose that they are ridiculously expensive. As a rule, a high-quality OTC cream costs around $20-$40 a tube, about twice as much on a per-volume basis as an equivalent-strength Rx cream.
Other ingredients
So how are we to know what you are getting? To begin with, look at the cream itself. A simple cream that has just progesterone and a vehicle is much less likely to elicit allergic reactions or confuse the picture with other hormone-like ingredients.
All creams are in an oil-based vehicle. While you may find one brand is better-absorbed by your skin than another, it doesn't make much functional difference otherwise.
Some brands claim to have better storage and metabolic clearance characteristics because of variations on a "liposomal delivery system." We're not totally convinced about this, since these reviews are written solely by those who are selling it. If this were such a hot idea, more retailers (and pharmacists!) would be offering this kind of vehicle and there would be discussion of it by other than those directly reaping profit from its sales. Still, if it makes you happy, go for it—it's probably not going to hurt anything but your wallet.
We also have serious qualms about the other contents of some creams. In addition to various botanicals (and the risk of allergy), many contain DHEA and/or pregnenolone, two hormone precursors we don't feel are safely taken unless you can clinically demonstrate a primary deficiency of them. In this as in all things hormonal, we really feel that it makes sense to take all you need, but also to take no more than you need. If one is good, two just provides a disposal problem for your body. It's a TANSTAAFL thing.
A usual starting dose of progesterone cream for women in surgical menopause who are also taking estrogen seems to be in the range of 15-25 mg a day. We'll talk more about tuning this dose elsewhere, but it makes sense when shopping otc to look for a cream strength that puts this into a reasonable volume for application. It's also important to actually figure out one's dose in the strength purchased—just blindly following the label directions for using so many teaspoons is an instruction almost invariably written for women in natural menopause.
Age and handling matter
The next important aspect of OTC progesterone use is where you're getting it and what kind of care they are taking of the supply. Progesterone deteriorates with age, light, air, and heat exposure. A dusty store with sales-oriented staff ("no, buy this one that has more things in it and costs more, and by the way, you probably need some of this too") and old, leaking jars that smell rancid—this is not going to provide a good, reliable pharmaceutical-grade hormone supply. When you find an acceptable brand and supplier, stick with it.
Shopping
You are going to have to do a little work in picking brands. There were once sites that did ingredient testing and published verifiable brand content, but since women have decreased their use of this hormone in response to newer information about risks, there really aren't these kinds of guides online or the ones that remain are too outdated to be of use.
You will be able to locate a number of brands in health food stores, body shops and online sources—but it's worth checking around as retail stores often charge more than an internet order, even taking shipping into account. A number of companies also offer specials from time to time that may help with the cost. If you have a friend who can make a recommendation, great—but you still owe yourself the time to take care with looking over the vendor and reading the label carefully to make sure it's what you want. And just because it works great for your friend/hairdresser/neighbor doesn't mean that the vehicle it's in will agree with your skin. It's not unusual for women to try out more than one brand before they hit on the one they prefer.