Hormonal Update Volume 1 Number 4

In a woman’s HRT program her individuality plays a very important role and, as we are going to discuss in this bulletin, the specific nature of replacement hormones also plays a role. Understanding how each works will help determine the one most appropriate for you.

For many years hormone replacement therapy (HRT) has been prescribed for women in one-size-fits-all doses of tablets made from synthetic or animal-derived hormones. Now, replacement hormones not only come in a multitude of dosages, they also come in natural, bio-identical forms and are available in a variety of delivery systems: capsules, creams, gels, patches, and sublinguals.

Each of these forms and delivery systems has different dynamics in the body. In other words, each is absorbed and metabolized differently. Whether or not a hormone is animal-derived, synthetic, or bio-identical will affect how it works in the body. Some delivery systems act very quickly; others have a more sustained, even effect.

If a replacement hormone does not raise your hormone level to a desired target zone, it won’t be effective. Contrarily, if HRT raises your hormone level too high, or too quickly, you can experience undesirable side effects. This doesn’t mean you have to give up HRT but just that you may have to reevaluate your program. Simply raising or lowering your dosage, or changing from one delivery system to another may be all that is necessary. By becoming familiar with how replacement hormones work, you will be able to choose not only what you are most comfortable using, but also what works best for your body.

The replacement hormones most commonly prescribed today are synthetic or animal-derived. Manufactured and marketed by major pharmaceutical companies, they include Premarin® (animal-derived estrogens) and Provera® (synthetic progesterone) as well as all brands of oral contraceptives. These compounds may or may not be chemically similar to your own hormones, but they are definitely not an exact match. Premarin and Provera have been the basis for most of the hormonal scientific experimentation carried out; however, they are no longer the only choices available.

Natural, bio-identical hormones such as estradiol and progesterone are available now and gaining in popularity. Produced by pharmaceutical companies, hormones are manufactured from a plant source (usually soybeans or yams) and have structures that match exactly the molecular structure of your own hormones. That means when a bio-identical hormone meets with a hormone receptor in your body the fit is the same as if it were your own hormone.

The ideal way to take replacement hormones is to take ones that are identical to the ones your body produces in the amounts your body needs to function optimally.

Whether a hormone is taken by mouth or applied to the skin impacts not only how much of the hormone actually enters the bloodstream but also the rate at which it takes place. The amount of hormone entering your bloodstream is important because it determines your hormone level. Understanding different delivery systems will help you better understand your response to replacement hormones.

Orals: Capsules and Tablets

When you take a hormone orally, in tablet or capsule form, the hormone first passes through your digestive system before it becomes available to your tissues. During the digestive process, and what is known as first-pass elimination by your liver, about 80 to 90% of the hormone is removed from your circulation leaving about 10 percent of the original dosage accessible.

Transdermals

Transdermal hormones are those applied to your skin and are available as patches, creams, and gels. Because transdermally applied hormones do not go through a first-pass elimination by your liver, dosages are significantly lower than those of other delivery systems.

The use of transdermal hormones makes it possible for substantially lower doses of replacement hormones to achieve the same effect as higher doses of oral preparations. Comparing results from oral preparations, current scientific literature demonstrates similar heart and bone protection with the lower transdermal doses of bio-identical hormones. With minimal doses, a woman may now receive the maximum benefit from her hormone replacement program. Many pharmaceutical companies are recognizing this advantage and are introducing lower dose patches.

Hormone patches, which resemble small band-aids and are applied to the torso, are effective and convenient. More importantly, patches mimic your own hormone-releasing patterns very closely. They provide you with very even, constant hormone levels. A hormone patch application can last for three to seven days depending on the brand. Even though most patches still only come in standard doses, there are a number available to choose from. Some adhesives used in patches can cause irritation, however this varies from woman to woman. If one bothers you, you can try another.

Transdermal creams are an excellent way many women take advantage of HRT. Even though patches and creams both fall within the transdermal category, they work differently. Creams must be applied daily, generally twice a day and usually do not provide continuous hormone delivery. But, not all cream bases are the same. Depending on the base composition, some preparations are able to slow the rate of hormone absorption allowing delivery over a more extended period. Compounding pharmacists can assist with these products. It is important to remember that it is possible to transfer transdermal hormones to another person on contact.

In addition to creams and patches, sublingual (under the tongue) hormone drops and dissolving capsules are also generally considered transdermals because they are absorbed through the mucous membrane under the tongue. Absorbed in the mouth, sublinguals are not subject to first- pass elimination by the liver like tablets and capsules therefore dosages are generally much lower than orals.

Scientific researchers are constantly searching for better, safer, and more effective methods of hormone replacement which, along with concerned consumers, encourages the pharmaceutical industry to develop lower dose, natural, bio-identical replacement hormone preparations. Currently, dozens of different brands, delivery systems and dosages are available to choose from. However, because women have such a variety of hormone products at hand, it can be challenging to sort through them all. In our next bulletin, Hormonal Update No. 5, we will provide an overview of the current market and describe the similarities and the differences between many of the natural and synthetic hormone preparations.