Day 10 on Mounjaro: Dramatic Weight Loss, and Even Greater Fears About What Happens After Stopping (2)

\r\n\r\n[The Financial News] On the 19th, I received my first 2.5 mg injection of Mounjaro, a Glucagon-like peptide-1 (GLP-1) obesity treatment. Exactly one week later, on the 26th, I injected the second pen, and as of the 28th, it has been 10 days since I started treatment.
One clear change after 10 days is that my mornings feel much better. After starting Mounjaro, I became very sleepy in the early evening and went to bed earlier, which led to deeper sleep. I have also been avoiding caffeine and alcohol as much as possible so as not to interfere with the drug’s effect, and that likely helped my sleep as well. My waist size has noticeably shrunk to the point that I can feel it when I put on my clothes. 
Feeling my body get lighter in just ten days made me curious about my actual weight. I had originally planned not to worry about the scale until I returned to the hospital a month later for an additional prescription. But I couldn’t resist and ended up ordering a scale online. The number I saw was shocking: I was down 3.7 kg.
In fact, I have tried several diets in the past where I lost more than 10 kg in just two or three months. From those experiences, I already knew that if you sharply cut your food intake at the beginning, you quickly lose a lot of water weight. What was different this time, however, was that I did not have to grit my teeth to endure hunger, and I did no exercise at all beyond the walking I do commuting to and from work. Thanks to Mounjaro’s effect, my meals naturally ended when I had eaten only about 30–40% of my usual amount, and my weight dropped accordingly.
Ultimately, this still means I am “losing weight by not eating.” Mounjaro is a drug that suppresses appetite and slows gastric emptying, creating early and prolonged satiety. It is also said to support insulin secretion and regulate fat metabolism, improving how efficiently the body uses energy. But at its core, it helps you lose weight by reducing how much you eat. That is why the rapid weight loss does not feel purely joyful. Because the drug is restricting my intake, my weight could go back up at any time once I stop taking it. I am increasingly afraid of what will happen when I come off this medication that forcibly suppresses my appetite.
In reality, about five days after the first injection, I gradually began to feel hungry again between meals. I assumed it was simply time for the next shot and administered the second pen, but it did not trigger as immediate a response as the first. I wondered if my body had already adapted to the 2.5 mg dose. Mounjaro can be increased to 5 mg, 7.5 mg, and up to a maximum of 15 mg. Typically, patients go through four pens at 2.5 mg to adjust, and it is generally said that the full effect begins in earnest from 5 mg.
On day 10, I now feel hungry at each mealtime, and if I really wanted to, I feel I could easily finish a full single serving. But I am forcing myself to hold back, worried that the weight I have already lost will come right back. This leaves me wondering: is my current weight loss due to Mounjaro, or is it my own willpower, driven by not wanting to waste the money I spent on the drug?
Commonly known side effects such as nausea, vomiting, and diarrhea have not appeared. The only side effects I have felt are slight lethargy and fatigue. On this, Yong-ho Lee, a professor of Endocrinology at Severance Hospital and General Affairs Director of the Korean Diabetes Association (KDA), stated, "Clinical results show that about 5–10% of patients report fatigue or a sense of weakness. As the medication reduces carbohydrate intake, the body has less immediate energy source in the form of glucose, and as the brain’s energy source shifts, symptoms such as fatigue can occur." He continued, "These symptoms occur most often at the start of treatment or when increasing the dose, and they gradually improve within 2–4 weeks as the body adapts to the drug. Maintaining adequate nutrition and sufficient fluid intake can help."
wonder@fnnews.com Jung Sang-hee Reporter