A 39-year-old female patient in the first trimester of pregnancy, presenting with hyperthyroidism, prior history of subclinical hypothyroidism, and hyperemesis gravidarum. Do you have a preference in prescription?”—PTU is one drug that’s used for hyperthyroidism, for Graves, versus methimazole, which is another drug that’s used. Both are extremely hepatotoxic. PTU is more hepatotoxic, and methimazole, as Debbie points out, has risk of potential birth defects in the first trimester.—“The patient showed negative for Graves antibodies, but endocrinologist felt strongly that the patient did have Graves.”

Chris Kresser: Yeah, I have some personal experience with this, actually. Back when my wife and I were trying to get pregnant, after about a year or a year and a half of trying, I thought, OK, something’s not right. I did some testing and found that my wife had low TSH and high thyroid hormones, and actually in her case, she did have positive thyroid antibodies. The antibodies that are most specific for Graves are TSI antibodies. You’ll also sometimes see elevated thyroglobulin and TPO antibodies, but TSI are the most specific for Graves. The endocrinologist that we saw prescribed PTU, and me being me, I did some research on it and said, heck, no, unless there’s no other option. Basically I just ended up treating her with Chinese and Western herbs and some supplements, and then also she started low-dose naltrexone. I see, Debbie, that you asked that as a follow-up question, and in her case, it completely resolved the issue, and it was only three months after that that she ended up getting pregnant.

LDN, I’ve seen have remarkable effects in Graves disease—and Hashimoto’s, for that matter. We had another patient that had been on PTU or methimazole, one of the two—I can’t remember—for 20 years, two decades, and I was even skeptical that LDN would help, given that she had been on a thyroid-suppressing drug for that long. And sure enough, she started taking LDN, and within a few weeks, she had gone hypothyroid because the dose of methimazole that was necessary to calm her thyroid when she was not on LDN was then too big of a dose once she started taking LDN, which has the effect of calming down the thyroid hyperactivity, as well. So she went in to her doctor and started to talk to him about titrating off of the medication, and now she’s been medication free for the past two and a half years. When it works, it really works. It’s certainly worth trying. There’s not a lot of data on low-dose naltrexone in pregnancy, but there’s a fertility clinic in the UK that uses it for fertility, and they continue their patients with LDN all the way through pregnancy and have never had an issue. I felt comfortable enough with it after researching low-dose naltrexone to advise my wife to take it all the way through her pregnancy and had no issues, and I would feel personally safer with my wife taking low-dose naltrexone during her pregnancy than PTU or methimazole by a mile. No contest at all.