Active ingredients in weight loss medications
Modern weight loss medications can provide medical support for people with obesity or significant excess weight when lifestyle measures alone are not sufficient. What matters is not only the name of a medication, but above all the active ingredient it contains, how it works in the body, medical suitability, approval status, and physician supervision.
Important: Weight loss medications are not freely usable lifestyle products. Whether an active ingredient is medically appropriate depends on several factors, including BMI, pre-existing conditions, current medication, possible contraindications, previous weight loss attempts, and the individual treatment goal. At The Body Clinic, patients can have their medical suitability for weight loss medications assessed.
Well-known active ingredients used in medication-based weight loss today include semaglutide, tirzepatide, and liraglutide. There are also other active ingredients and active ingredient concepts such as naltrexone/bupropion, orforglipron, and retatrutide, which differ significantly in mechanism of action, administration, clinical evidence, approval status, and availability.
Active ingredients in medical weight loss
What is the difference between an active ingredient and a medication?
The active ingredient is the substance that produces the medical effect in the body. The medication is the approved medicinal product that contains this active ingredient. One example: semaglutide is an active ingredient. Wegovy, Ozempic, and Rybelsus are medications that contain semaglutide, but they may have different approved uses, dosage forms, and doses.
For patients, this distinction is important because not every medication with the same active ingredient is automatically suitable or approved for the same treatment. Treatment goal, administration, risks, contraindications, and medical indication can also differ.
- Active ingredient: medically active substance, for example semaglutide, tirzepatide, liraglutide, or naltrexone/bupropion
- Medication: approved medicinal product with a specific active ingredient, for example Wegovy, Mounjaro, Saxenda, or Mysimba
- Active ingredient class: medical classification according to mechanism of action, for example GLP-1 receptor agonist or GIP/GLP-1 receptor agonist
- Indication: medical use for which a medication is approved
- Treatment decision: individual medical assessment based on health status, goals, risks, availability, and suitability
Important active ingredients in weight loss medications at a glance
The following overview shows important active ingredients and active ingredient concepts that are frequently searched for in connection with medical weight loss. It is important to distinguish whether they are established active ingredients in approved medications, an active ingredient combination that is not currently offered, or an experimental active ingredient in clinical development.
| Active ingredient | Active ingredient class | Known medications or status | Typical classification |
|---|---|---|---|
| Semaglutide | GLP-1 receptor agonist | Wegovy, Ozempic, Rybelsus | Depending on the medication, type 2 diabetes or medical weight management |
| Tirzepatide | GIP/GLP-1 receptor agonist | Mounjaro | Type 2 diabetes and weight management with an appropriate medical indication |
| Liraglutide | GLP-1 receptor agonist | Saxenda | Weight management with appropriate medical suitability |
| Naltrexone/bupropion | Centrally acting active ingredient combination | Mysimba | EU-approved active ingredient combination; not currently offered by The Body Clinic |
| Orforglipron | Oral, non-peptide GLP-1 receptor agonist | Foundayo in the United States | Approved in the United States; no regular approval or availability documented for Germany/EU at this time |
| Retatrutide | GLP-1/GIP/glucagon receptor agonist | Experimental active ingredient | In clinical development; no regular approval or availability documented for Germany/EU |
How active ingredients in weight loss medications may affect the body
Many modern active ingredients for weight loss act on the body’s own hormonal systems, which influence hunger, satiety, blood sugar regulation, and food intake. Incretin-based active ingredients are particularly relevant. These include GLP-1 receptor agonists, dual GIP/GLP-1 receptor agonists, and experimental triple agonists that also target the glucagon signaling pathway.
These active ingredients do not act at only one single point in the body. They can influence several signaling pathways that are jointly involved in how strongly hunger is perceived, how long satiety lasts, how the body responds to food, and how metabolic processes are regulated.
- Brain: Signaling effects may help increase the feeling of fullness and reduce hunger, appetite, or cravings.
- Stomach: Some active ingredients can slow gastric emptying. This may help the feeling of fullness after eating last longer.
- Pancreas: Incretin-based active ingredients can influence insulin secretion in connection with food intake and may therefore play a role in blood sugar regulation.
- Gut and metabolism: The body’s own incretin hormones, such as GLP-1 and GIP, are part of a finely tuned signaling system between the gut, brain, and metabolic organs.
- Energy balance: Experimental active ingredients such as retatrutide are also being investigated because they additionally influence signaling pathways linked to energy and metabolic regulation.
GLP-1 receptor agonists such as semaglutide and liraglutide are based on the effects of the body’s own hormone GLP-1. Among other things, they may increase the feeling of fullness, reduce hunger and appetite, and slow gastric emptying. This can make it easier for patients to reduce calorie intake.
Tirzepatide additionally acts through two signaling pathways: GLP-1 and GIP. This is why tirzepatide is often described as a dual GIP/GLP-1 receptor agonist. Retatrutide, as an experimental triple agonist, goes one step further and is being studied in connection with GLP-1, GIP, and glucagon. However, the specific suitability for treatment, possible risks, and the appropriate form of therapy must always be assessed individually by a physician.
Active ingredients in weight loss medications compared
Which active ingredient may be appropriate cannot be decided based on search queries, patient reports, social media posts, or before-and-after images alone. Active ingredients in weight loss medications differ in several ways, including mechanism of action, administration, tolerability, clinical evidence, approved use, availability, and actual treatment offering.
| Criterion | Semaglutide | Tirzepatide | Liraglutide | Naltrexone/bupropion | Orforglipron | Retatrutide |
|---|---|---|---|---|---|---|
| Active ingredient class | GLP-1 receptor agonist | GIP/GLP-1 receptor agonist | GLP-1 receptor agonist | Centrally acting active ingredient combination | Oral GLP-1 receptor agonist | GLP-1/GIP/glucagon receptor agonist |
| Known medications or status | Wegovy, Ozempic, Rybelsus | Mounjaro | Saxenda | Mysimba | Foundayo in the United States | Experimental active ingredient |
| Administration | Injection or tablet, depending on the medication | Injection once weekly | Injection once daily | Tablet | Tablet | Studied as an injection in clinical trials |
| Key characteristic | GLP-1 active ingredient available in different dosage forms | Dual mechanism of action through GIP and GLP-1 | GLP-1 active ingredient with daily administration | Combination of naltrexone and bupropion with a central mechanism of action | Non-peptide, orally administered GLP-1 active ingredient | Experimental triple agonist targeting GLP-1, GIP, and glucagon |
| Classification at The Body Clinic | To be assessed depending on the medication and medical suitability | To be assessed depending on the medication and medical suitability | To be assessed depending on the medication and medical suitability | Not currently offered | Not currently offered | Not currently offered |
| To be assessed by a physician | Indication of the specific medication, current medication, risks, and treatment goal | BMI, comorbidities, tolerability, contraindications, and treatment goal | Suitability, daily administration, side effects, and long-term treatment strategy | BMI, blood pressure, current medication, mental health, seizure risk, and opioid use | Approval status, availability, current medication, tolerability, and treatment goal | Approval status, clinical data, side effects, long-term safety, and individual suitability |
Which active ingredient classes are used in weight loss medications?
Different active ingredient classes play a role in medical weight loss. Incretin-based active ingredients such as GLP-1 receptor agonists and dual GIP/GLP-1 receptor agonists are especially frequently searched for today. There are also other active ingredient classes that may be relevant depending on the country, approval status, medical situation, and individual suitability.
- GLP-1 receptor agonists: Active ingredients such as semaglutide or liraglutide, which can influence satiety, appetite, food intake, and blood sugar-related processes.
- GIP/GLP-1 receptor agonists: Dual-acting active ingredients such as tirzepatide, which target two hormonal signaling pathways.
- GLP-1/GIP/glucagon receptor agonists: Experimental triple agonists such as retatrutide, which are being studied in clinical trials.
- Oral GLP-1 active ingredients: Active ingredients such as orforglipron, which are developed or used as tablets and differ from injectable GLP-1 therapies.
- Centrally acting active ingredient combinations: Combinations such as naltrexone/bupropion, which do not work like GLP-1 active ingredients, but may influence central regulatory mechanisms of appetite and eating behavior.
- Lipase inhibitors: Active ingredients such as orlistat, which can influence the absorption of dietary fats.
Which active ingredient class is medically appropriate should not be decided in general terms. At The Body Clinic, it is assessed as part of weight loss medications for medical weight management whether medication-based support may be suitable and, if so, which option may be appropriate.
Which active ingredients are currently available and which are not?
For patients, not only the effect of an active ingredient matters, but also its current status. Some active ingredients are contained in approved medications and may be part of treatment depending on medical suitability. Other active ingredients are approved but are not currently offered by The Body Clinic. Others are still in clinical development.
| Category | Active ingredients | Classification |
|---|---|---|
| Established active ingredients in approved medications | Semaglutide, tirzepatide, liraglutide | May be medically relevant depending on the medication, indication, and physician assessment. |
| Approved active ingredient combination, not currently offered | Naltrexone/bupropion | Contained in Mysimba; not currently offered by The Body Clinic. |
| New oral active ingredient with international momentum | Orforglipron | Approved in the United States; no regular approval or availability documented for Germany/EU at this time; not currently offered by The Body Clinic. |
| Experimental active ingredient in clinical development | Retatrutide | Not a regularly approved weight loss medication in Germany/EU at this time; not currently offered by The Body Clinic. |
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Who may be suitable for active ingredients in weight loss medications?
Weight loss medications are not suitable for everyone. They are usually considered when significant excess weight or obesity is present and medical treatment may be appropriate. BMI, weight-related comorbidities, and previous weight loss attempts often play an important role.
A medical assessment is especially important if additional health risks are present, if patients take medication regularly, or if symptoms are unclear.
- Obesity or significant excess weight
- Weight-related comorbidities such as high blood pressure, prediabetes, type 2 diabetes, or dyslipidemia
- Previous unsuccessful weight loss attempts despite dietary changes and physical activity
- Increased health risk due to weight
- A desire for medical supervision instead of independent medication use
- Assessment of side effects, contraindications, and interactions
At The Body Clinic, a specific active ingredient is therefore not recommended automatically. Instead, physicians individually assess whether medication-based weight loss, a program for weight loss with injections and medical supervision, treatment with weight loss tablets after medical assessment, or a concept for weight loss without medication with an individual plan may be better suited.
What role do side effects play?
Active ingredients in weight loss medications can be medically helpful, but they can also cause side effects. With incretin-based active ingredients, gastrointestinal symptoms such as nausea, vomiting, diarrhea, constipation, or abdominal pain are frequently described. Headaches, appetite changes, fatigue, or intolerances may also occur.
Which side effects are relevant depends on the active ingredient, dose, speed of dose escalation, dosage form, and individual health situation. This is why treatment should always be medically supervised.
Careful assessment is especially important in cases of:
- existing gastrointestinal conditions
- metabolic disorders such as type 2 diabetes
- cardiovascular disease or increased cardiovascular risk
- regular use of other medications
- previous intolerance to weight loss medications
- pregnancy, breastfeeding, or plans to become pregnant
- unclear symptoms before starting treatment
Patients can find more detailed information on individual medications in our overviews of side effects of Mounjaro, side effects of Wegovy, and side effects of Saxenda.
How can you get weight loss medications in Germany?
Medications with active ingredients such as tirzepatide, semaglutide, or liraglutide are prescription-only. They should not be used without medical assessment, obtained from unsafe sources, or taken according to a self-directed dosing schedule.
At The Body Clinic, the process therefore begins with a medical suitability assessment. This clarifies whether medication-based weight loss may be an option, which active ingredient could be appropriate, and what type of medical supervision is needed. Patients who would like an initial overview can find more information about available treatment options on the page weight loss medications overview.
Active ingredients that are not currently regularly available, are still in clinical development, or are not offered by The Body Clinic should not be obtained independently. Online offers, social media sources, or unverifiable shops can pose risks due to incorrect dosing, unverified quality, lack of medical supervision, or counterfeit products.
Medical weight loss at The Body Clinic
The Body Clinic supports patients on their path to medically grounded weight loss. The focus is not on quickly using a specific active ingredient, but on an individual treatment concept. This includes medical assessment, personal consultation, medical follow-up, and a realistic evaluation of which type of therapy fits the patient’s starting point.
Depending on medical suitability, programs with weight loss injections, tablets, or without medication may be considered. Patients can find information about program costs on the page prices for medical weight loss. Patients who would like to clarify directly whether treatment may be an option can book a consultation for medical weight loss.
Frequently asked questions about active ingredients in weight loss medications
Which active ingredients are used in weight loss medications?
The most important active ingredients in modern weight loss medications include semaglutide, tirzepatide, and liraglutide. There are also other active ingredients and active ingredient concepts such as naltrexone/bupropion, orforglipron, retatrutide, or orlistat. Which active ingredient is suitable must be assessed individually by a physician.
What is the difference between an active ingredient and a medication?
The active ingredient is the medically active substance. The medication is the specific medicinal product that contains this active ingredient. This means that medications with the same active ingredient can have different uses, doses, dosage forms, or treatment goals.
Which active ingredient class is particularly relevant in weight loss medications?
GLP-1 receptor agonists and dual GIP/GLP-1 receptor agonists are currently discussed especially often in connection with medical weight loss. New active ingredient concepts such as oral GLP-1 active ingredients or triple agonists are also being studied scientifically. Whether an active ingredient class is suitable depends on the individual medical situation.
Are weight loss medications available without a prescription?
Many relevant weight loss medications with active ingredients such as tirzepatide, semaglutide, or liraglutide are prescription-only. Use without medical assessment is not recommended and may carry health risks.
Are there active ingredients in weight loss medications that are available as tablets?
Some active ingredients are available as tablets depending on the specific medication, or are being developed as tablets. Rybelsus, for example, contains semaglutide in tablet form, but it is a medication for the treatment of type 2 diabetes. Orforglipron is an oral GLP-1 active ingredient; however, no regular approval or availability has been documented for Germany/EU at this time. Whether a tablet or injection is medically appropriate should be assessed by a physician.
Which active ingredients belong to GLP-1?
GLP-1 receptor agonists include semaglutide and liraglutide, among others. Tirzepatide also acts through GIP and is therefore classified as a GIP/GLP-1 receptor agonist. Retatrutide is being studied as an experimental triple agonist because it targets GLP-1, GIP, and glucagon.
Is naltrexone/bupropion a GLP-1 active ingredient?
No. Naltrexone/bupropion is not a GLP-1 therapy, but a centrally acting active ingredient combination. It differs significantly from active ingredients such as semaglutide, tirzepatide, or liraglutide.
Is retatrutide already approved as a weight loss medication?
At this time, retatrutide is not a regularly approved weight loss medication in Germany or the European Union. The active ingredient is still in clinical development and is not currently offered by The Body Clinic.
Is orforglipron available in Germany?
Orforglipron is receiving significant international attention as an oral GLP-1 active ingredient. However, no regular approval or availability has been documented for Germany and the European Union at this time. The Body Clinic does not currently offer orforglipron.
How quickly do weight loss medications work?
The effect does not start at the same pace for everyone. Many treatments begin with a low dose that is gradually increased. Weight development, tolerability, and treatment progress should be monitored regularly by a physician.
Does health insurance cover the costs?
Whether and to what extent costs are covered depends on the individual case, the insurance provider, and the specific reason for treatment. In many cases, weight loss medications have to be paid for privately. A binding assessment is only possible after an individual review.
Sources
- European Medicines Agency: Mounjaro, active ingredient tirzepatide, EPAR and product information.
- European Medicines Agency: Wegovy, active ingredient semaglutide, EPAR and product information.
- European Medicines Agency: Saxenda, active ingredient liraglutide, EPAR and product information.
- European Medicines Agency: Mysimba, active ingredients naltrexone and bupropion, EPAR and product information.
- Reuters: Eli Lilly says next-gen obesity drug helps patients lose 28% of body weight, 2026.
- Jastreboff AM et al.: Triple-Hormone-Receptor Agonist Retatrutide for Obesity. New England Journal of Medicine, 2023.
- ClinicalTrials.gov: A Study of Retatrutide (LY3437943) in Participants Who Have Obesity or Overweight, TRIUMPH-1.
- Reuters: EMA backs Novo’s Wegovy pill, first oral weight-loss drug for Europe, 2026.