What is Mounjaro?
Mounjaro (brand name for tirzepatide) is a prescription that is used to treat high blood sugar in adults with type 2 diabetes [1, 2]. It is an injectable medicine that helps with blood sugar by acting like two hormones in your body (glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), agonists) [1, 3].
What does Mounjaro do?
One of Mounjaro's most vital functions is enabling blood sugar control. It prompts the release of insulin, one of the hormones used to keep blood sugar in an ideal range. When GIP concentrations get higher, the beta cells in the pancreas secrete more insulin. GLP-1 also encourages insulin secretion and causes a slowdown in how fast your stomach empties its contents (gastric emptying). The insulin release and slowing gastric emptying can help you feel full longer [1].
Aside from being prescribed for blood sugar management (generally for patients with type 2 diabetes), Mounjaro is also used off-label as a weight-loss medication for obesity [1, 4]. In other words, while blood sugar management (and weight loss) may be important goals, these are best achieved when used alongside a diet and exercise programme [2].
What is Hashimoto's Disease?
Hashimoto’s disease, or Hashimoto’s thyroiditis, is an autoimmune disorder in which the body’s immune system attacks the thyroid gland, causing it to become underactive (hypothyroidism) and impair critical bodily functions. The thyroid is a gland in front of the neck that secretes hormones that help regulate metabolism, body temperature and muscle strength. If the thyroid is attacked and damaged, it can impair these critical bodily functions [5, 6, 7].
Causes of Hashimoto's Disease
Hashimoto’s disease is thought to arise from a combination of genetic and environmental influences, although what the exact culprits are remains unclear. Twin studies have shown that genetic factors can account for about 55% of the variance, meaning that, if one identical twin has the condition, almost 1 in 2 of their twins will have it as well. In contrast, only 3% of the same-sex, nonidentical twins will develop it [5].
Additional environmental triggers, such as a viral infection, exposure to radiation, or certain drugs, may also cause Hashimoto’s thyroiditis in susceptible individuals if the immune system misrecognizes the thyroid cells as foreign and mounts an attack against them [5, 8]. Over time, this attack—and the inflammation that comes with it—may destroy thyroid tissue.
In some individuals, Hashimoto’s disease develops after an existing autoimmune disease, such as Graves’ disease. At least 15-20 per cent of Graves’ patients go on to develop Hashimoto’s [9].
Certain dietary factors like food additives, refined flours, refined sugar and nutritional deficiencies in antioxidant nutrients, trace elements such as selenium, potassium, iodine, copper, magnesium, zinc, iron and B vitamins, and vitamins A, C and D can play a role in its development [10].
Can You Take Mounjaro with Hashimoto's Disease?
Tirzepatide, marketed as Mounjaro, is a prescription medication used to treat blood sugar levels in adults with type 2 diabetes. It acts as an atypical GLP-1 receptor agonist and GLP-2 agonist, essentially ‘imitating’ intestinal hormones involved in signalling satiety and triggering the release of insulin that slows blood sugar [1, 2].
However, the only direct evidence we have to date for Mounjaro’s treatment of Hashimoto’s disease, which is a type of thyroiditis, is that it causes thyroid cancer. Mounjaro has a boxed FDA warning for causing thyroid cancer – and your doctor is unlikely to prescribe it to you or a member of your family if you or the member of your family has one particular type of thyroid cancer or one particular type of thyroid illness [11, 4].
Although Mounjaro had been used off-label for weight loss and insulin resistance, the drug just improves insulin resistance but is not equivalent to treating Hashimoto’s disease [12].
In conclusion, while Mounjaro has proven useful for managing type 2 diabetes and weight loss, no studies have suggested that it can help treat thyroid conditions like Hashimoto’s. It’s imperative that you ask your healthcare provider for specific medical recommendations for your individual needs.