Thyroid replacement medication
Levothyroxine (Eltroxin or Synthroid)
We track thyroid levels closely for women attempting to conceive. If left unchecked, hypothyroidism (too little thyroid activity) or hyperthyroidism (too much) will lead to poor outcomes with fertility treatments. Fortunately, thyroid disorders are usually straightforward to diagnose and treat.
The most sensitive way to track thyroid activity is by measuring TSH levels. TSH is the hormone that drives the thyroid, and its levels vary with thyroid activity, but are usually between 0.35 to 4.2 mIU/L. When the thyroid is underactive, TSH levels will be too high. Your physician will work with you to ensure your levels are optimal when you are trying to conceive.
How is hypothyroidism treated?
This is treated by taking a thyroid hormone replacement, in the form of a small oral pill taken daily. A prescription for levothyroxine (“Eltroxin” or “Synthroid”) will be faxed to your pharmacy.
How do I take my thyroid replacement?
- Please take it on an empty stomach with water only.
- We often recommend taking it first thing in the morning when you wake up. Please continue to take it around the same time each day.
- Wait 1 hour before eating or drinking. Drinking water is okay.
- Do not take any other vitamins or supplements with your thyroid replacement, as they may affect absorption of your medication.
What dose do I need to take?
The dose of thyroid replacement in adults ranges and will depend on your unique circumstances.
Doses available for levothyroxine (mcg):
| Dose (mcg) | Dose (mcg) |
|---|---|
| 25 | 125 |
| 50 | 137 |
| 75 | 150 |
| 88 | 175 |
| 100 | 200 |
| 112 | 300 |
Are there side effects?
There are very few side effects, and it produces almost no allergic reactions.
What if I miss a dose?
Please take it as soon as you remember you missed a dose.
If you realize you missed a dose at your next scheduled dose, please skip the missed dose.
Do I need to recheck my TSH level?
Once treatment begins, we will repeat TSH levels in a few weeks to ensure that you are taking an accurate dose.
Do I need to see a specialist to manage my thyroid?
Depending on your circumstances, your physician may refer you to an endocrinologist who specializes in thyroid management. If so, we will ensure a referral is completed and sent out for you. Further thyroid testing and medication management will be through the endocrinologist.
When do I stop taking thyroid replacement?
You will continue thyroid replacement daily, unless advised by your physician to stop.
Once you are pregnant, there is no contraindication to taking thyroid replacement throughout your pregnancy. We check TSH levels for all of our pregnant patients and we will often increase your dose. If you are already taking thyroid replacement, there is no harm in reminding us that you too may need to have your dose increased.
If you have an endocrinologist or GP managing your thyroid, we will work with them to ensure you are on the appropriate thyroid dose during your early pregnancy care with us.