There are two main reasons to take blood tests:
Everyone absorbs and metabolises hormones and medication differently. For a lot of drugs, this is taken into consideration during the discovery and testing process. However, with bio identical hormones the medication dose is a fixed, so it is more common for people to need different doses. Blood tests allow an understanding of how much of the hormone is circulating in the body so that the adjustments to the dose can be made.
Some people are predisposed to some conditions and reactions to medications like blockers can impact the kidneys and liver, blood tests will catch these issues much earlier than symptoms will show. Liver or kidney issues can cause some markers to rise and alert that something is going wrong.
The following tests are monitored to help with adjusting dosing. Different doctors and endocrinologists will most likely monitor subsets of these, and different ones are more or less important testosterone therapy or estrogen therapy. On top of that, if a blocker is being used and which one will make different tests more important.
| Test | Testosterone or Estrogen | Aiming for |
|---|---|---|
| Testosterone | Both | Reference range |
| Estradiol | Estrogen | Rough reference range |
| Progesterone | Estrogen | Rough reference range |
| Luteinising Hormone | Both | Less than 1 |
| Follicle-Stimulating Hormone | Both | Less than 1 |
| Sex Hormone Binding Globulin | Estrogen | Less than 100 |
The following test are mostly likely done at the start when a baseline is done and ongoing depending on the type of therapy and medication used. These tests are trying to look for side effects of the hormone therapy including the use of blockers.
| Test | Reason |
|---|---|
| Full Blood Count | Testosterone therapy can increase red blood cell count |
| Urea and Electrolytes | Testing for kidney issues and care taking with Spironolactone |
| Renal Function Test | Testing for kidney issues |
| Liver Function Test | Testing for liver issues |
| Glucose & hba1c | Diabetes is impacted by hormones |
| Lipids | Cholesterol (LDL and HDL) levels are impacted by hormones |
All methods of HRT lead to peaks and troughs in hormone levels based on when the dose is taken / applied. Generally you want to measure your levels at the trough which lets you know the lowest point of your exogenous and highest point of your endogenous hormone.
Knowing the highest point of your endogenous hormone is important because generally you want to keep this suppressed during HRT as it will interfere with progress.
Exactly when to test will depend on your dosing schedule and route.
| Dosage Route | Frequency | Test timing |
|---|---|---|
| Pill | 1x per day | Just before when you take your regular dose |
| 2x per day | Before your first dose of the day | |
| 3x per day | Before your first dose of the day | |
| Gel | 1x per day | Just before when you take your regular dose |
| 2x per day | Before your first dose of the day | |
| Patch | 1x per week | Just before your regular dose |
| 2x per week | Just before your morning dose | |
| Injection | - | Just before your regular dose |
| Implant | - | Every 3 months or less |
If you need to delay the dose, it should only be for a few hours.