When a medicine may be considered
The NIDDK explains that clinicians define overweight and obesity with body mass index (BMI), a ratio of weight to height. A BMI from 25 to 30 counts as overweight, and 30 or more as obesity [1].
According to the NIDDK, a clinician may prescribe a weight medicine to an adult with a BMI of 30 or more, or with a BMI of 27 or more plus a weight-related health problem such as high blood pressure or type 2 diabetes. It adds that these medicines are not for everyone with a high BMI: some people can lose weight with a lifestyle programme alone [1].
Medicines do not replace healthy eating and activity, the NIDDK says; they work best as part of a lifestyle programme [1]. It also warns that in some cases side effects may outweigh benefits, which is why a medicine should never be taken only to improve how you look [1].
What each label is approved for, and who it rules out
Each US label describes its weight indication in section 1 and its contraindications in section 4. The table summarises the four GLP-1 products with a weight indication as checked for this article. In the main trials behind these labels, obesity meant a BMI of 30 or more and overweight a BMI of 27 to under 30 [3][5].
| Product (label date) | Weight indication (section 1) | Not to be used (section 4) | Pregnancy and contraception |
|---|---|---|---|
| Wegovy® injection and tablets (06/2026) [2] | Injection: adults and children aged 12 and older with obesity, and adults with overweight plus a weight-related condition. Tablets: adults only. Also heart-risk reduction; MASH for the injection | Personal or family history of MTC, or MEN 2; known allergy to semaglutide or an ingredient | Stop when pregnancy is recognised; for a planned pregnancy, the label puts the stop at least 2 months beforehand (8.1, 8.3) |
| Zepbound® (08/2026) [3] | Adults with obesity, or overweight plus a weight-related condition; also moderate to severe obstructive sleep apnoea in adults with obesity | Personal or family history of MTC, or MEN 2; known serious allergy to tirzepatide or an ingredient | Stop when pregnancy is recognised; may reduce the effect of oral hormonal contraceptives (7.2, 8.3) |
| Saxenda® (02/2026) [4] | Adults, and children aged 12 and older weighing more than 60 kg with obesity | Personal or family history of MTC, or MEN 2; serious allergy to liraglutide or an ingredient | Weight loss offers no benefit in pregnancy and may harm the fetus (8.1) |
| Foundayo™ tablets (07/2026) [5] | Adults with obesity, or overweight plus a weight-related condition | Personal or family history of MTC, or MEN 2; known serious allergy to orforglipron or an ingredient | Pregnancy exposure registry; may reduce the effect of oral hormonal contraceptives (7.3, 8.1) |
Your history matters more than you think
Your clinician will want to know your weight over the years, what you have already tried, and your current health problems [1].
Family history counts too. As the table shows, each of these labels rules the medicine out if you or a relative has had a rare thyroid cancer called medullary thyroid carcinoma, or if you have an inherited condition called MEN 2 [2][3][4][5]. The NIDDK adds that weight medicines should not be taken during pregnancy or while planning one, that they are not recommended while breastfeeding, and asks you to mention allergies and every medicine, supplement and herbal product you take [1].
Contraception is part of that list. The Zepbound® and Foundayo™ labels explain that they may lower the effect of birth control pills, and describe what prescribers advise in section 8.3 and section 7.3 respectively [3][5]. Our article on GLP-1 medicines and oral contraceptives covers this brand by brand.
How a medicine is chosen
The NIDDK calls the choice a decision between you and your clinician, and lists what goes into it: the benefit you are likely to get from losing weight, the possible side effects, your other health problems and medicines, your family’s medical history, and cost [1].
GLP-1 medicines are only one group. The NIDDK table of approved long-term options also includes orlistat, phentermine-topiramate and naltrexone-bupropion, and each has its own reasons not to be used [1]. The GLP-1 options themselves differ in form: weekly injections, a daily injection and daily tablets, as their labels describe [2][3][4][5].
Availability can also shape the choice. On 20 October 2026 the FDA Drug Shortages Database listed liraglutide injection as in shortage, with Saxenda® at limited availability and due to be discontinued in January 2027, according to the manufacturer’s entry [8].
Where the NIDDK page has fallen behind
The NIDDK page is a good starting point, but it was last reviewed in June 2024. Its list of approved weight medicines names Wegovy® and Zepbound® but not the Wegovy® tablets, approved in December 2025, or Foundayo™, approved in April 2026 [1][9].
It also says the FDA was still looking into reports of suicidal thoughts or actions with certain weight medicines [1]. Since then, the Recent Major Changes boxes of the Wegovy® (01/2026), Saxenda® (02/2026) and Zepbound® labels list their warning section on suicidal behaviour and ideation as removed [2][3][4]. Changes in mood still belong in any conversation with your clinician.
Questions worth bringing
- Is this an approved use, or off-label? The NIDDK explains that off-label means using a medicine differently from its approval, and says you should feel comfortable asking [1].
- How will we know it is working? According to the NIDDK, if 12 weeks at the full dose bring a loss below 5% of the weight you started with, your clinician will probably advise stopping [1]. The Saxenda® label sets its own check at 16 weeks (section 2.2) [4].
- How long would I take it? The NIDDK says people who are benefiting without serious side effects may stay on it indefinitely [1].
- What happens if I stop? The NIDDK says you will probably regain some weight [1].
- Which side effects are common, and which mean I should call you?
- Do my other medicines need adjusting, including diabetes medicines or birth control pills [1][3][5]?
- Will my insurance cover it? The NIDDK says some plans do and some do not, and suggests asking your insurer [1].
- Where should I fill it? The NIDDK suggests a pharmacy approved by your clinician, and the FDA advises a state-licensed pharmacy [1][6].
Realistic expectations
The NIDDK gives an honest range. On average, after one year, adults taking a weight medicine as part of a lifestyle programme lose 3% to 12% more of their starting weight than people in the programme without medicine, and results vary by medicine and by person [1].
Even modest loss can count. The NIDDK says losing 5% to 10% of your starting weight may lower blood sugar, blood pressure and triglycerides, and that most weight loss happens in the first six months [1].
Online and telehealth prescriptions
If you consider an online service, the FDA’s advice is to get a prescription from your doctor and fill it at a state-licensed pharmacy [6]. Its BeSafeRx pages link to each state’s pharmacy licence database, say not to use an online pharmacy that is not listed, and suggest confirming that a listed pharmacy requires a prescription, gives a US address and phone number and has a licensed pharmacist to answer questions [7].
- A company that claims a compounded drug is the same as an approved one [6].
- Prices that seem too good to be true [6].
- No screening and prescription by a licensed doctor before the medicine is sent, or no doctor available afterwards [6].
- Medicine that looks different, arrives damaged or without instructions, or a label with spelling errors or a pharmacy name you think may be fraudulent [6].
Bring a few weeks of numbers
A short record is easier to discuss than memory: your weight on the same scale over several weeks, notes on meals and sleep, and your medicine list.
Wegovy® and Saxenda® are registered trademarks of Novo Nordisk A/S. Zepbound® is a registered trademark and Foundayo™ a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.
