By Dr. Asnat Raziel, bariatric surgeon specializing in obesity treatment, metabolic health and healthy longevity; Director of the Multidisciplinary Center for Obesity Treatment, Assia Medical, Assuta Ramat HaChayal, Tel Aviv
Getting the Foundayo dosage right is the key to good results with fewer side effects. In this practical guide, I explain how the dose is raised step by step, why the tablet doses look different from the doses in the trials, what to do if you miss doses, and which safety points to discuss with your doctor.
Foundayo in brief: a daily pill for obesity
Foundayo contains the active ingredient orforglipron (Orforglipron), a new drug in the GLP-1 family taken as one pill a day. The FDA approved it for obesity treatment in the US in April 2026. Its main advantage is convenience: there is no injection, and you can swallow the pill at any time of day, with or without food. In its large trial, people on the highest dose lost an average of 11.2% of their body weight over 72 weeks.
How Foundayo works in the body
GLP-1 is a natural hormone that the gut releases after a meal. It signals fullness to the brain, slows stomach emptying and helps balance blood sugar. The familiar drugs in this family, such as semaglutide, are small proteins. That is why most of them are injected, and their pill version must be taken on an empty stomach with a wait before eating.
Orforglipron, by contrast, is not a protein but a small molecule. It is well absorbed from the gut, so it has no food or drink restrictions. In practice, it reduces hunger and thoughts about food, much like the other drugs in this family. I compare it in detail with the semaglutide pill in my article on Foundayo versus oral semaglutide. I also wrote about how GLP-1 drugs act on the hunger centers in the brain.
What the trials showed
The main trial is called ATTAIN-1, and NEJM published its results. It enrolled 3,127 adults with obesity and without diabetes. For 72 weeks, participants took one of three doses or a placebo, along with a healthy diet and physical activity.
- 6 mg dose: average weight loss of 7.5%.
- 12 mg dose: average weight loss of 8.4%.
- 36 mg dose: average weight loss of 11.2%.
- Placebo: weight loss of only 2.1%.
Put simply, out of 100 patients on the highest dose, about 55 lost at least 10% of their weight, and about 18 lost 20% or more. In the placebo group, only about 13 out of 100 reached a 10% loss. In addition, the researchers found improvements in waist size, blood pressure, triglycerides and non-HDL cholesterol.
It is important to know that these numbers include people who stopped treatment. Among those who stayed on the highest dose, average weight loss reached 12.4%, compared with 0.9% in the placebo group.
Even before that, a meta-analysis of phase 2 trials with 774 participants showed clear weight loss compared with placebo. More on the phase 3 results appears in my article on the phase 3 studies behind the pill.
Foundayo dosage: how the dose is raised
In the trials, the researchers gave the drug as capsules. However, the approved drug is a tablet, so its doses are different. According to the manufacturer, a 17.2 mg tablet matches the exposure of the 36 mg capsule tested in the trials.
- Start with 0.8 mg once a day.
- After at least 30 days, go up to 2.5 mg, and then to 5.5 mg.
- Next, depending on response and tolerance, the dose can go up to 9, 14.5 or 17.2 mg.
- The maximum dose is 17.2 mg a day.
Whatever your Foundayo dosage, swallow the tablet whole, without breaking or chewing it. The gradual increase aims to reduce nausea and other digestive side effects. Also, if you miss a full week of doses in a row, you will need to restart at a lower dose, as your doctor advises.
Foundayo dosage vs. trial doses: why the numbers differ
Many patients are confused when they read about 36 mg in the studies and then see a top dose of 17.2 mg on their prescription. The explanation is simple. The trials used capsules, while the approved product is a tablet that is absorbed differently. Therefore, the 17.2 mg tablet is the counterpart of the 36 mg capsule. In other words, the 11.2% average weight loss from ATTAIN-1 refers to the top tablet dose. So a lower number on the box does not mean a weaker treatment. It is the same exposure in a different form.
Side effects and safety while raising the Foundayo dosage
The side effects of orforglipron are similar to those of other GLP-1 drugs, and most involve the digestive system. According to the prescribing information, about 35% of patients on 17.2 mg reported nausea, compared with 10% on placebo. Constipation, diarrhea, vomiting and heartburn also occurred. In most cases, these effects were mild to moderate and appeared mainly during dose increases. In ATTAIN-1, between 5.3% and 10.3% of patients stopped treatment because of side effects, compared with 2.7% on placebo.
Who should not take it
As with all drugs in this family, the US label includes a warning about thyroid tumors. Therefore, doctors must not give it to anyone with a personal or family history of medullary thyroid cancer or MEN 2 syndrome. In addition, talk with your doctor about past pancreatitis, gallbladder disease and kidney disease.
An important point for women: the drug may make birth control pills less effective. So the advice is to add a barrier method of contraception for 30 days after starting treatment and after each dose increase. Also, do not combine it with another GLP-1 drug.
Who Foundayo is for
In the US, the FDA approved the drug for adults with obesity, or with overweight and at least one weight-related condition, such as high blood pressure. Doctors always prescribe it alongside a balanced diet and physical activity. In Europe, the European Medicines Agency’s medicines committee recommended approval in October 2026 for obesity and type 2 diabetes. As of early November 2026, the final decision still rests with the European Commission. You can read about the situation in Israel in my article on Foundayo in Israel.
The pill is especially suitable for people who fear injections, travel a lot or find it hard to take a pill on an empty stomach. On the other hand, average weight loss is slightly lower than with the strongest injectable drugs. So the choice should be personal. My articles on drug treatment for obesity cover all the options.
Another important question is what happens after weight loss. A dedicated trial tested whether the pill can maintain weight after injection treatment, and I summarized it in my article on keeping weight off after the shots. A broad review of the new obesity pill and how treatment works is also available on the site.
The bottom line on Foundayo dosage
With the right Foundayo dosage plan, this is a convenient and effective treatment option: one pill a day, no food restrictions and an average weight loss of about 11% at the high dose. However, it is not right for everyone, and it requires a gradual dose increase and medical follow-up. If you are considering drug treatment, it is worth building a plan with a doctor who knows the field. You can read more about my approach to treatment on my About page.
The information in this article is general and does not replace personal medical advice.
Questions and answers
What is the difference between orforglipron and Foundayo?
There is none. Orforglipron is the name of the active ingredient, and Foundayo is the drug’s brand name.
What is the maximum Foundayo dosage?
The maximum dose is 17.2 mg once a day. You reach it gradually, with at least 30 days at each step.
Does the Foundayo dosage depend on meals?
No. Unlike the semaglutide pill, you can swallow it at any time, with or without food.
How much weight do people lose on Foundayo?
In the ATTAIN-1 trial, people on the high dose lost an average of 11.2% of their weight over 72 weeks. Results vary from person to person.
What are the common side effects?
Mainly nausea, constipation, diarrhea and vomiting. In most cases they are mild and fade over time, especially when the dose is raised gradually.
Sources
Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment
Foundayo (orforglipron) Prescribing Information
EMA Panel Backs Lilly’s Foundayo for Obesity and Type 2 Diabetes in Europe
Eli Lilly funded the ATTAIN-1 trial.
