I have to say, when I first mentioned seeing something on the internet to my doctor years ago I got a total eye roll and a lecture that everything on the internet is false and dangerous advice. Over the years things have changed. There are now actually credible sources of information. But if you just google, you can come up with whack jobs like this website and Martin Hum PhD DHD nutritionist. In case you don’t know what DHD stands for it is Disability and Human Development. When I looked him up he is associated with the supplement scam operation I looked into last June. Not a credible source of advice.
I have to tell you, every GLP-1 drug comes with a warning. Yes, even Byetta. And absolutely if you have or have had thyroid cancer you probably should not use a GLP-1 drug until there is a better understanding of the risk. Every drug carries some risk of adverse effects, whether it be gastric distress with metformin, weight gain or hypos from insulin or excessive bleeding with aspirin. All these risks should be taken in context. GLP-1 drugs like Byetta and Trulicity have been associated with thyroid cancer in rats. One human patient (of many thousands) in the Trulicity study had thyroid cancer. It wasn’t clear whether Trulicity played a role and the FDA could not conclude that there was any connection, hence the black box warning. Byetta missed the same warning by a single patient. The bottom line, they have both been associated with thyroid cancer in rats, but there isn’t sufficient evidence to conclude that in humans. The FDA has a “watch” program where the thousands (if not millions) of patients are observed for thyroid cancer. If Trulicity (or Byetta) does cause thyroid cancer it will show up and the FDA may alter it’s approval of the drug. If no thryoid cancer shows up then the FDA will remove the warning.
At this time switching from Trulicity to Byetta probably does nothing about those risks. You can talk to your doctor about your concerns, but he will likely ask you why you suddenly worried about Trulicity but never had any issue with Betta.
ps. If you really want to know about black box warnings on these drugs your should read the prescribing information for Byetta and Trulicity. That information is carefully reviewed and approved by the FDA.