The Boys star Erin Moriarty announced that she has been diagnosed with Graves’ disease.

“Autoimmune disease manifests differently in everybody/every body. Your experience will be different from mine,” Moriarty, 30, wrote via Instagram on Saturday, June 14. “My experience will be different from yours. Perhaps greatly, perhaps minutely. One thing I can say: if I hadn’t chalked it all up to stress and fatigue, I would’ve caught this sooner.”

According to the Mayo Clinic, Graves’ disease impacts the thyroid by causing the body “to make too much thyroid hormone.” Symptoms can include irritability, mood swings, rapid weight loss, tiredness, difficulty sleeping and a lower sex drive, among others. The autoimmune condition is more prevalent in women and tends to impact people older than 30 most often, the Mayo Clinic states.

Moriarty explained to her Instagram followers that she has already seen improvement after starting treatment “a month ago.”

“Within 24 hours of beginning treatment, I felt the light coming back on. It’s been increasing in strength ever since,” she noted. “If yours is dimming, even slightly, go get checked. Don’t ‘suck it up’ and transcend suffering; you deserve to be comfy. S***’s hard enough as is.”

The SAG Award nominee shared photos and text messages from her Graves’ disease journey, including a harrowing text she sent her mother at the height of her suffering.

“I’m serious; I really really need relief,” she wrote. “I feel nauseated tonight. I feel so s*** and removed from who I am, I can’t live like this forever. Or that long. There aren’t moments anymore, not even a passing 5 seconds, when I feel normal. I’ve never had that. Not one. It’s not just fatigue – it’s an ineffable, system-wide cry for help and I don’t know how long I can remain in this state.”

In sharp contrast to that alarming message, Moriarty included another text message to her father about how much better she felt after beginning treatment.

“I already feel a world of a difference, primary thought (as of now): ‘Damn, this is how I’m supposed to feel? I’ve been missing out,’” she declared.

Moriarty received huge support for going public with her diagnosis, with The Boys costar Susan Heyward and See actress Nesta Cooper both sending her heart emojis.

The Boys director Shana Stein also wished Moriarty well by replying, “So happy you’re on the road to healing.”

Moriarty rose to fame – and earned a Screen Actors Guild Award nomination – for her supporting performance in the 2016 drama Captain Fantastic. She followed it up with a well-received role as Hope Shlottman in Jessica Jones and starred in the 2018 true-crime comedy Driven opposite Ted Lasso actor Jason Sudeikis and Bodies Bodies Bodies’ Lee Pace.

For the past four seasons, Moriarty has portrayed the reluctant superhero Annie January (a.k.a. Starlight) in Prime Video’s The Boys. The streamer confirmed Moriarty will return for the fifth and final season of The Boys, which is expected to premiere in 2026.