Welcome to The Thin Line, a series exploring the less recognized aspects of GLP-1 drugs. While medications like Ozempic have aided countless individuals in managing weight and diabetes, they come with certain risks. Stay tuned for more insights into the not-so-well-known downsides of these popular treatments.
Brooke Hinderhan believed she’d made a positive turn in her health journey.
After metformin didn’t effectively manage her diabetes, she started taking Ozempic. Initially, the widely used GLP-1 drug helped stabilize her blood sugar levels.
Even the side effects seemed manageable at first — until she experienced severe fatigue, along with intense stomach cramps and diarrhea that left her in agony.
“I thought it was just the Ozempic,” shared Hinderhan, a 47-year-old registered nurse from Norris, Illinois.
However, she later discovered the situation was much more severe: cancer had developed in her colon, and what she had dismissed as mere side effects were actually early indicators of the illness.
Her ordeal reflects a growing trend on social media, where users of GLP-1 drugs and their families discuss how these medications may be concealing serious health issues, sometimes delaying timely diagnosis and treatment.
Many of these cases involve colorectal cancer, a condition increasingly prevalent among younger Americans. It’s currently the leading cause of cancer-related deaths in adults under 50 in the U.S., with numerous patients being diagnosed at advanced stages after attributing symptoms to harmless issues like hemorrhoids or IBS.
“I think most of what I was going through was likely side effects from the tumor, but it’s hard to say if the Ozempic contributed to how I felt,” Hinderhan noted. “It all kind of blended together.”
From concern to crisis
With her symptoms worsening, Hinderhan’s doctor switched her to Mounjaro, another GLP-1 medication designed to help regulate blood sugar, appetite, and cravings.
The doctor mentioned Mounjaro had fewer side effects, but for Hinderhan, the issues persisted and even intensified.
“I was experiencing extreme fatigue that was overwhelming,” said the mother of four. “It really affected my daily life because I was just so tired.”
By February 2025, her weight dropped rapidly, and she started noticing bloody, foul-smelling stools.
Having just reached 45 — the age recommended for starting colorectal cancer screenings — she scheduled a colonoscopy but ultimately canceled it, downplaying her concerns.
She later took a Colorguard test at home, which returned positive results. That’s when fear set in.
A colonoscopy was scheduled, but she didn’t get to it. About a month before that appointment, she felt severe pain in her side while at work.
“My first thought was, ‘Oh, I’m going to die.’ Then it hit me, ‘I should have gone in sooner,’” she recalled.
“I ended up in the ER thinking I might need an appendectomy, but I walked out knowing I had a large mass in my colon.”
The tumor had grown to the size of a baseball, nearly blocking her colon completely, with the pain stemming from significant constipation.
A colonoscopy and biopsy confirmed the diagnosis: stage 2 adenocarcinoma, along with a splenic fracture.
“Having worked as a hospice nurse for eight years, my initial reaction was, ‘Oh, I’m going to die.’ Then I thought about how I should have come in earlier, but I honestly didn’t feel like anything was wrong until the last few weeks.”
When cancer red flags and GLP-1 side effects overlap
Colorectal cancer often advances unnoticed, but early signs can include changes in bowel habits, abdominal pain, unexplained weight loss, fatigue, anemia, and blood in stools.
“Some side effects caused by GLP-1 agonists, such as constipation and bloating, can mimic symptoms of colorectal cancer,” explained Dr. David Greenwald, a gastroenterology expert who did not treat Hinderhan.
“It’s challenging to distinguish between the two,” he added. “You can’t use weight loss as an indicator.”
A spokesperson from Novo Nordisk stated that semaglutide, the active ingredient in Ozempic and Wegovy, has undergone extensive clinical trials.
“We acknowledge that some patients may face gastrointestinal side effects that are generally temporary and can improve over time,” they noted.
Eli Lilly, the maker of Mounjaro, stressed that patient safety is their top priority, assuring that they actively monitor and report safety information.
Greenwald mentioned specific symptoms that should raise red flags.
“GLP-1s won’t cause rectal bleeding or notable narrowing of the stool; these signs need evaluation by a healthcare provider because they’re not normal.”
If detected early, over 90% of colorectal cancer patients can survive at least five years, but that drops to about 13% once the cancer spreads, according to the American Cancer Society.
“The positive aspect is that colorectal cancers typically grow slowly,” Greenwald added. “Delays that extend over years can lead to later stages of cancer, which are associated with poorer outcomes.”
A life-changing diagnosis
Michelle Lyson is experiencing this reality herself. Five years prior to her cancer diagnosis, her doctor suggested a GLP-1 for managing diabetes, weight loss, and polycystic ovary syndrome.
“It worked well; I had great blood sugar control and lost more than 100 pounds,” said Lyson, 55. However, she quickly developed gastrointestinal issues.
“Sometimes I’d be very constipated, while at other times I’d find myself going four or five times a day,” she explained. “Whenever I raised it with my doctor, she just attributed it to Ozempic.”
In January, she found blood in her stool, and tests revealed she was anemic.
“At the time, my doctor and I weren’t too concerned,” Lyson recalled. “I really believed it was all just the GLP-1s.”
“I often reflect on all the years I fussed over wanting to be thin, and I wish I could reclaim that time to focus on my health,” she added.
Her doctor ordered a Cologuard test, which came back positive, leading her to a colonoscopy that confirmed the diagnosis.
“Once I received the cancer diagnosis, I sensed it would likely be worse than anticipated because everything fell into place, and I realized, ‘Hey, this has been going on for five years,’” she reflected.
During the surgery, doctors found the cancer had spread to her peritoneum, classifying it as stage four.
“That elevates the stage,” she explained.
Now, she faces six months of chemotherapy followed by another surgery aimed at removing as much of the cancer as possible. They’ll also be administering heated chemotherapy directly into her abdomen to target any lingering cancer cells.
Since her diagnosis, Lyson had to stop GLP-1s, resulting in a rapid weight gain of over 40 pounds—a common occurrence when individuals discontinue these medications.
“It’s incredibly disheartening,” she said. “I managed to keep it off for so long, yet I think I’d prefer to focus on being alive at this point.”
Not a ‘golden ticket’ after all
Following her diagnosis, Hinderhan underwent surgery to remove the tumor, parts of her colon, her gallbladder, and 52 lymph nodes. Complications arose during the surgery, leading to an eight-day hospital stay with a feeding tube, followed by an extensive recovery period.
Initially, doctors thought she would require chemotherapy, but upon testing the lymph nodes, they found no signs of cancer spread.
“That felt miraculous to me,” Hinderhan expressed.
Today, she is cancer-free and back on a GLP-1 to manage her diabetes.
“I’ve shed a lot of weight, my inflammation has reduced, and I give credit for that to the GLP-1,” she stated. “I’m no longer experiencing the symptoms I had previously.”
Despite everything, she doesn’t regret her decision to take the medication.
“Looking back, I wasn’t aware of what was causing my feelings,” she noted. “Had I followed advice and gotten my colonoscopy on time, perhaps this wouldn’t have happened.”
Lyson shares a similar sentiment: “Had I known earlier that I needed to watch for this, I might still have tried it,” she said.
Her message is straightforward: pay attention to your body, adhere to screening recommendations, and understand that GLP-1s aren’t always the “golden ticket” they’re perceived to be.
“They do promote weight loss, and they quiet cravings, but it’s crucial to consider whether the trade-off is worth it,” she offered.
“Because where I stand now, I often reflect on all those years I spent wanting to be thin, and I wish I could have concentrated on my health instead.”
