Euthyrox vs. Synthroid for Thyroid Cancer and Hypothyroidism: Important Differences and Potential Risks.

Levothyroxine

Synthroid

(levothyroxine)

Summary for Euthyrox

Prescription only

Levothyroxine is a thyroid hormone used to treat low thyroid hormone levels (hypothyroidism) in people of all ages. It's also approved to help treat thyroid cancer along with radioactive iodine and surgery. The medication is available in tablet and liquid forms and is taken once daily, usually on an empty stomach in the morning. Regular blood tests are needed to keep your dose in the right range. Common side effects happen when the dose is too high and can include fast heartbeat, anxiety, and weight loss.

Indications for Euthyrox

Hypothyroidism (low thyroid hormone levels)
Thyroid cancer, together with radioactive iodine and surgery

Pros and Cons for Euthyrox

Pros

First-choice medication for treating low thyroid hormone levels
Safe to use during pregnancy
Only needs to be taken once a day
Available as a liquid solution (Tirosint Sol, Thyquidity, and Ermeza)

Cons

Must be taken on an empty stomach
Might take several weeks to find the right dose
Requires regular blood tests
Interacts with many foods, medications, and supplements

Common Side Effects for Euthyrox

Signs of having too much thyroid hormones in the body, such as:

Irregular heartbeat
Chest pain
Shortness of breath
Leg cramps
Headache
Nervousness
Hives or skin rash
Irritability
Trouble sleeping
Tremors
Muscle weakness
Change in appetite
Weight loss
Vomiting
Diarrhea
Sweating a lot
Sensitivity to heat
Fever
Changes in menstrual period

Warnings for Euthyrox

Not for weight loss
Heart problems
Adrenal crisis in people with adrenal insufficiency
Worsening diabetes
Bone loss

Summary for Synthroid

Prescription only

Synthroid (levothyroxine) is a thyroid hormone used to treat low thyroid hormone levels (hypothyroidism) in both children and adults. It's also used to treat a certain type of thyroid cancer. The medication comes as tablets in many different strengths. It's taken once a day by mouth, usually on an empty stomach in the morning. You'll need regular blood tests to make sure you're getting the right dose. Side effects can include headache, trouble sleeping, and weight loss.