Navigating Your HRT Journey: A Guide to Hormones, Dosing, and Personalization

Starting hormone replacement therapy (HRT) for perimenopause or menopause can feel like a significant step. It's the most effective treatment for managing common symptoms like hot flushes, brain fog, and mood changes, but the world of gels, patches, and different hormones can seem confusing.

You might be wondering: What are these hormones? Why is my dose different from my friend's? And how do I know it's working? This guide breaks down the key components of HRT to help you understand how it works and why your treatment is tailored specifically to you.

The Key Players: Understanding Your Hormones

HRT works by supplementing the hormones your ovaries are no longer producing. The main hormones used are estradiol, progesterone, and sometimes testosterone.

1. Estradiol (The "Symptom Soother")

Estradiol is the primary form of estrogen your body produced during your reproductive years. You have estrogen receptors in virtually every part of your body, from your brain to your bones and skin.

This is why falling estrogen levels can cause such a wide range of symptoms:

• Brain: Regulates temperature (causing hot flushes), supports memory, and works with neurotransmitters like serotonin to stabilize mood.

• Bones: Essential for maintaining bone density and strength.

• Heart: Provides cardiovascular protection.

• Other Areas: Maintains muscle and joint health, supports metabolism, and keeps vaginal and vulval tissues healthy and lubricated.

The goal of estrogen in HRT is to replenish these levels, relieving your symptoms and providing long-term health benefits.

2. Progesterone (The "Womb Protector")

If you still have your uterus (womb), you will need to take progesterone alongside estrogen. Estrogen on its own can cause the lining of the womb (the endometrium) to thicken, which increases health risks.

Progesterone's job is to protect the endometrium and keep it thin.

• Who needs it: Anyone with a uterus.

• Who doesn't: Women who have had a hysterectomy.

• Common type: Many women use body-identical micronized progesterone (e.g., Utrogestan). A hormonal coil (like the Mirena) also works wonderfully for this.

3. Testosterone (The "Energy Booster")

Testosterone isn't just a male hormone. Women produce it too, and it's crucial for energy, motivation, concentration, and libido (sex drive). Levels of testosterone also fall during menopause, and replacing it can be transformative for women experiencing these specific symptoms.

Body-Identical vs. Synthetic: What Is HRT Made From?

You may have heard stories about HRT being made from horse urine. While this was true for older, tablet-only forms, modern HRT is very different.

The vast majority of HRT prescribed today is body-identical. This means the hormones are derived from plants (like yams or soy) and are engineered to have the exact same molecular structure as the hormones your own body produces.

• Estrogen: The most common form is 17-$\beta$ estradiol.

• Progesterone: Micronized progesterone (e.g., Utrogestan) is a common body-identical option.

• Testosterone: Also plant-derived and available as a gel or cream.

How Hormones Are Taken (And Why It Matters)

Estrogen can be taken in two main ways:

1. Orally (Tablet): This form is swallowed and must be processed by your liver. This processing slightly increases the risk of blood clots.

2. Transdermally (Through the Skin): This includes gels, patches, and sprays. The hormone is absorbed directly into your bloodstream, bypassing the liver.

Benefits of Transdermal Estrogen:

• No increased clot risk: This is the biggest advantage.

• Safe for migraines: It's the recommended form for women who experience migraines.

• Flexible dosing: It is very easy to adjust your dose up or down.

Finding Your Dose: Why HRT Is Not "One Size Fits All"

Your HRT dose should be completely individualized, with the goal of relieving your symptoms and improving your long-term health (protecting your heart, bones, and brain).

Are blood tests needed?

• For diagnosis: No. Menopause is diagnosed based on your age and symptoms. Hormone levels fluctuate so much in perimenopause that blood tests are unreliable for diagnosis.

• For monitoring: Yes, sometimes. Blood tests can be very useful to check how well you are absorbing transdermal HRT (patches, gels). They aren't as accurate for oral estrogen.

If you're still having symptoms on HRT, a blood test can help your doctor see if your estrogen is being absorbed properly. For most women, a blood level of over 250 pmol/l is the target for symptom relief and long-term health benefits.

Studies show that younger women often need higher doses of HRT to reach these therapeutic levels compared to older women. In fact, a study from Newson Health found that nearly one in three women using standard licensed doses had low blood estradiol levels, suggesting their dose was not high enough for them.

"My friend is on a lower dose than me. Is mine too high?"

This is a very common question, and the answer is almost always no. Absorption is the key. Two women can use the exact same dose, but their bodies will absorb it completely differently.

Some women find they absorb gels better than patches, while others find the opposite. Even different brands of patches can absorb differently from person to person. Because of this, you may need a higher dose to achieve the same blood level as someone else.

The Great Absorption Mystery: Why Are We All So Different?

Why does one woman need one pump of gel while another needs four? It comes down to individual physiology.

• Skin Biology: The thickness of your skin, its hydration level, and even its temperature can affect absorption.

• Blood Flow: Your skin is fed by tiny blood vessels (capillaries) that absorb the hormone. The number and depth of these vessels vary for everyone.

• Skin Enzymes: Your skin contains enzymes that can break down the hormone before it even reaches your bloodstream.

• Ethnicity: Some research indicates that absorption rates can differ across ethnic groups. One study found that individuals with a Hispanic background had the highest absorption rate, followed by White, Asian, and Afro-Caribbean individuals.

Dosing Details for Progesterone and Testosterone

Progesterone Dosing

A common misconception is that if you increase your estrogen, you must also increase your progesterone. This is not supported by evidence.

The dose of progesterone is not dependent on your estrogen dose. Its job is simply to protect the womb.

• Cyclical (if you still have periods): Usually 200mg of Utrogestan taken for 12-14 days a month.

• Continuous (if periods have stopped): Usually 100mg of Utrogestan taken every night.

Some bleeding is common in the first 3-6 months of starting HRT. However, if you have any unexpected bleeding after this, you should always discuss it with your doctor.

Testosterone Dosing

Testosterone is usually started at a low dose (e.g., 5mg of gel daily). After 3-6 months, your doctor will check your blood levels (Testosterone and SHBG, to calculate your Free Androgen Index). If your levels are still low and your symptoms (like low libido or brain fog) persist, your dose may be gradually increased.

Side effects are very rare as long as your levels are monitored and kept within the normal female range.

Your Key Takeaway

The goal of HRT is to find the right combination and dose that makes you feel your best. Your journey is unique, and your treatment should be too. Don't compare your dose to others—focus on your symptoms and work closely with a healthcare professional to find the perfect balance for you.