I think I'm allergic to hormones

You probably aren't. Think about it: you have had much higher levels of ovarian hormones in your body since puberty. If you were really allergic to them, you'd be more or less dead by now. Seriously, true allergy to one's own hormones is an incredibly rare condition. While low levels of estrogen can make our immune system more prone to taking offense at many previously-tolerated substances, that's a different situation entirely from having an allergic reaction to the hormones our hrt contains.

But I took HRT and they make me sick!

It's important to try to understand what aspect of any given hrt didn't agree with us rather than just writing them all off. By considering the matter in greater detail, we leave ourselves other avenues to pursue in meeting our hormone needs. So let's look at some of the things that cause unpleasant reactions.

True allergy to an ingredient

There are other things in all of our hrts besides the hormones they deliver. Some women are in fact allergic to the coloring agents in pills or the adhesive on a particular patch or the vehicle in which a cream hrt is prepared. One hrt that is a particular problem for those allergic to peanuts is Prometrium, which uses peanut oil as the suspension agent in its gelcaps.

If we already know we are sensitive to an ingredient or we break out in an ugly rash or suffer difficulty breathing, then we can rightly suspect that we need to work around an allergic response. But some detective work may be needed to determine just which aspect is causing the problem. All retail hrts list their full range of ingredients on the prescribing information package insert, including the "inactive" ones that color and bind them. Any compounding pharmacist can provide a woman with a similar list for any custom hrt they prepare for her.

If we take a pill, for example, and develop a reaction, rather than assuming we can never take any hrt ever again because it was the estrogen we responded so unfavorably to, we might well invest some time looking at what is in that particular hrt and then searching out a comparable one (by using our estrogen hrts page, for example) that doesn't have the same ingredients.

If our problem is with a patch, it's important to understand that in each brand of patch, the adhesive is the delivery system and for it to be patented, it must be different from every other brand of patch. That means that no other patch will exactly replicate the one that has just given us problems, and so by switching brands, we stand a good chance of leaving that problem behind.

In other words, for every hrt, then, we can do a little detective work and find an alternative that leaves out potential allergens.

As a side note on ingredients and allergies: don't expect your doctor to know much about hrt ingredients other than the hormone they deliver. It's just not important to them in most prescribing situations. This information is, however, recorded in the drug information, where it can be checked in such references as the PDR, product data sheets (which are linked from each estrogen or progestogen (or UK) brand here on the site), and through your pharmacist (who can also contact a manufacturer for you if there is a question that is not answered by the product data sheet).

What if all of the retail brands in our chosen delivery method contain this agent? Don't forget that compounding pharmacies can often prepare a similar hrt (in terms of route and active ingredient) that can leave out specific problematic ingredients. Just because we have allergies doesn't mean that we can't use any form of hrt: we just have to do a little more work getting it.

But I hated the way the hormones I took before made me feel

One special case we see often on hrt discussion forums is the concern voiced something like this:
I took birth control pills and they made me feel awful so I know that means I can't ever take hrt.
That's a really common misconception, so let's lay that one to rest right now.

Birth control pills contain larger amounts of hormones than hrts, and they typically contain both a synthetic estrogen and a synthetic progestogen (progesterone-like compound). Both of these agents are not human-identical in molecular structure, which means they are processed by the body differently from our own hormones. That's the idea with birth control pills: we don't want our bodies to use them for anything other than over-riding our own ovaries to prevent ovulation. But that very misalignment with our own chemistry means that we may respond differently to these agents than we do to our own estrogen and progesterone. HRTs contain lower doses and in many cases more human-identical hormones, so they are processed differently from oral contraceptives and they have different effect from them. Because of this distinction, then, gently-handled hrt is usually an entirely different experience from using oral contraceptives.

But there are many other ways an hrt can disagree with us that aren't true allergies.

Route-related effects

Some women have skin that doesn't especially like to be sealed up under a patch, any patch. Some women have digestive disorders or liver conditions that may mean that adding the burden of processing an oral hrt may cause uncomfortable symptoms like nausea. Women with inflammatory bowel disorders or endometriosis, for example, may find that vaginal hrts cause too much local stimulation and can be associated with diarrhea or cramping. All of these kinds of things are really due to the way we're putting the hrt into our bodies, not the actions of the specific hormone they contain.

In many cases we already know that we have these issues, and so when we select an hrt to try, it tends to make sense that we should choose routes that don't conflict with pre-existing problems. If your doctor isn't putting this together when he prescribes your first hrt, don't hesitate to mention something like "since I already have digestive issues, I'd really prefer an hrt in some other form than a pill." You know your own body than anyone else, so you can—and should—use that knowledge to head off possible problems.

What if you don't know? Then we have to reason our way to what might be the issue. This isn't necessarily complicated: if we have horrific nausea, it really makes sense to try to get around that by switching to a non-oral hrt. Just understanding that route of delivery has an effect on our bodies is part of the key to not writing off hrts entirely, but focusing in on what part of the hrt is being problematic.

Dose-related effects

These are the most tricky to grasp when we haven't yet been introduced to the idea of needs and hormones.

Hormones are active substances that fulfill certain needs in the body. We only need so much hormone work done at any given moment, however. If we don't have a great enough supply, some hormone work goes undone and we experience symptoms from what isn't covered. We all are familiar with one effect of undone hormone work: lack of thermoregulatory stability, which results in hot flashes. But there are many more effects of inadequate hormone supply, some of them quite unpleasant.

We need to differentiate these from negative effects of hrts, however, if we are to work effectively with our hrts. It's most frustrating when we take an hrt that doesn't deliver to our systems and we experience these effects, since it seems as though we're making ourselves worse with the hrt. But if we look at the effects of low estrogen, we can get a sense of the difference.

Now, if we take an hrt that contains an excess of hormones, such that more hormone work is being done than we need right then, we also develop symptoms. Again, while these can be very unpleasant, they don't mean that the hrt or the hormones are somehow wrong for our bodies; it just means that there's an excess of that work being done. This would include things like fluid retention and swelling, a normal effect of estrogen but one taken to an excessive level when our dose is too high. In this sort of situation, backing off on our dose until we reach a supply more closely aligned with our level of need will allow these symptoms to abate and a more comfortable "fit" with our hrt achieved.

There's lots of troubleshooting involved in this process and sometimes it's really not too clear which way we're trending. We spend a lot of time on our discussion forums discussing this sort of thing. What we're introducing here is the bare outline of the concept, roughed out so that you know that this can be one source of problems; it's not really a full exploration of the kinds and extent of problems that can occur with hrt dose mismatched to needs. We just want you to know that this can happen, and why it can be so unpleasant...without really being an allergy.