Semaglutide, tirzepatide, and retatrutide are all weekly injectable weight loss medications, but they work on a different number of hunger and metabolism hormones. Semaglutide acts on one (GLP-1), tirzepatide acts on two (GLP-1 and GIP), and retatrutide acts on three (GLP-1, GIP, and glucagon). In clinical trials that difference shows up in average weight loss, side effects, and, most importantly right now, FDA status: semaglutide and tirzepatide are FDA approved for weight management, while retatrutide is still investigational. Below, the medical team at Healthy Living Medical in Texarkana breaks down how they compare and how to decide which one fits you.

The short answer

• Semaglutide (brand names Wegovy and Ozempic) is a GLP-1 medication. In the STEP 1 trial, adults lost about 15% of their body weight on average over 68 weeks.
• Tirzepatide (brand names Zepbound and Mounjaro) is a dual GLP-1 and GIP medication. In the SURMOUNT 1 trial, adults on the highest dose lost about 21% of their body weight on average over 72 weeks.
• Retatrutide is a triple GLP-1, GIP, and glucagon medication developed by Eli Lilly. In its Phase 2 trial, adults on the highest dose lost about 24% of their body weight on average over 48 weeks. It is not FDA approved, and Lilly has said it plans to submit it to the FDA in early 2027.
• The best choice depends on your health history, how much weight you want to lose, how you tolerate side effects, and what is legally and safely available to you. That decision belongs in a conversation with a licensed provider.

What is semaglutide?

Semaglutide is a GLP-1 receptor agonist. It mimics glucagon-like peptide 1, a hormone your gut releases after eating that tells your brain you are full, slows how fast your stomach empties, and helps regulate blood sugar. It was first approved for type 2 diabetes as Ozempic and later for chronic weight management as Wegovy. In December 2025 the FDA also approved a daily Wegovy pill.

Semaglutide has the longest track record of the three, with years of real world use and a large cardiovascular outcomes trial (SELECT) showing a reduced risk of heart attack and stroke in adults with heart disease and overweight. For many people it is a strong, well understood starting point.

What is tirzepatide?

Tirzepatide activates two receptors: GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). GIP is another gut hormone involved in how your body handles sugar and fat. Adding it appears to boost appetite control and weight loss for many people. Tirzepatide is sold as Mounjaro for type 2 diabetes and Zepbound for weight management and obstructive sleep apnea.

In the SURMOUNT 5 trial, which compared the two medications head to head in adults with obesity, participants on tirzepatide lost about 20% of their body weight on average over 72 weeks, compared with about 14% on semaglutide. That is why tirzepatide is now one of the most searched weight loss terms in Texas.

What is retatrutide?

Retatrutide, sometimes called "reta," is a once weekly injection that activates three receptors: GLP-1, GIP, and glucagon. The glucagon piece is new. Glucagon may help the body burn more energy and break down liver fat, which is one reason researchers are excited about it. In a Phase 2 study published in the New England Journal of Medicine in 2023, adults on the 12 mg dose lost an average of about 24% of their body weight in 48 weeks, and Phase 3 results reported since then have continued to show large losses.

Here is what matters most: retatrutide is not FDA approved. As of October 2026, Eli Lilly has announced plans to submit a Biologics License Application in the first quarter of 2027, and it has opened a limited expanded access program through the FDA for certain patients. Approval, if it comes, is most likely in late 2027 or 2028.

Semaglutide vs tirzepatide vs retatrutide: side by side

• Hormones targeted: semaglutide 1 (GLP-1); tirzepatide 2 (GLP-1, GIP); retatrutide 3 (GLP-1, GIP, glucagon).
• Average weight loss in major trials: semaglutide about 15% at 68 weeks; tirzepatide about 21% at 72 weeks; retatrutide about 24% at 48 weeks (Phase 2).
• FDA status for weight loss: semaglutide approved (Wegovy injection and pill); tirzepatide approved (Zepbound); retatrutide investigational.
• Dosing: all three are weekly injections that start low and increase gradually. Semaglutide is also available as a daily pill.
• Most common side effects: nausea, constipation, diarrhea, reduced appetite, and fatigue for all three. Retatrutide trials also noted a dose-related increase in resting heart rate.

Which one causes the most weight loss?

Based on trial averages, retatrutide has shown the largest losses, followed by tirzepatide, then semaglutide. But averages hide a lot. Some people lose more on semaglutide than others do on tirzepatide, and some people cannot tolerate the higher doses that produce the biggest numbers. The "strongest" medication is not automatically the best one for you. The best medication is the one you can take consistently, safely, and long enough to change your health.

Is retatrutide safe? Can I buy it online?

Searches like "is retatrutide safe," "is retatrutide FDA approved," and "where to buy retatrutide" have exploded over the past year. Much of what is being sold online is labeled "research use only" or "not for human consumption." Those products are not made for patients, are not checked by a pharmacy for purity, sterility, or dose, and counterfeit versions have already been reported. Injecting a product of unknown origin is a real risk, no matter how good the trial results look.

If retatrutide interests you, ask any provider who brings it up exactly what product they are using, where it comes from, and how it fits current FDA rules. A legitimate clinic will answer those questions plainly. In the meantime, the two FDA approved options already produce meaningful, lasting results for most patients.

What about compounded semaglutide and tirzepatide?

Compounded medications are prepared by licensed pharmacies for individual patients. They are not FDA approved products, which means the FDA does not review them for safety, effectiveness, or quality before they are dispensed. Compounding can make treatment more affordable and allows dose adjustments, but quality depends heavily on the pharmacy. Ask where your medication is compounded, whether the pharmacy is state licensed, and what testing it performs.

How do I choose between them?

A good decision starts with your history, not the headlines. During a consultation, your provider should look at:

• Your weight loss goal and your past experience with diets or medications
• Conditions like type 2 diabetes, prediabetes, sleep apnea, high blood pressure, fatty liver, or heart disease
• Personal or family history of medullary thyroid cancer, MEN2, pancreatitis, or gallbladder disease
• How you handle side effects like nausea or constipation
• Cost, insurance coverage, and whether you prefer an injection or a pill
• Your plan for protecting muscle and maintaining results long term

How GLP-1 weight loss works at Healthy Living Medical

Our GLP-1 weight loss program in Texarkana starts with a complimentary consultation. We review your health history, talk through your goals, and help you understand each medication option before recommending a starting point. From there we guide your dosing, check in on side effects, coach you on protein and nutrition, and adjust as your body responds. If you are interested in shaping stubborn areas as you lose weight, we can also talk about Ultimate Contour body contouring.

Frequently asked questions

Is tirzepatide stronger than semaglutide?

In head to head research, tirzepatide produced more weight loss on average (about 20% vs 14% over 72 weeks). Many people still do very well on semaglutide, and some tolerate it better.

Is retatrutide FDA approved?

No. As of October 2026 retatrutide is investigational. Eli Lilly plans to submit it to the FDA in the first quarter of 2027.

Can I switch from semaglutide to tirzepatide?

Yes, many patients switch under medical supervision, usually because of a weight loss plateau or side effects. Your provider will choose a starting dose based on what you were taking.

Are semaglutide and tirzepatide peptides?

Yes. Both are peptide medications, meaning they are made of short chains of amino acids, which is why they often show up in conversations about peptide therapy.

Will I regain weight if I stop?

Weight regain is common after stopping GLP-1 medications. A maintenance plan that includes nutrition, strength training, and sometimes a lower ongoing dose helps protect your results.

Talk to a provider in Texarkana

If you are comparing semaglutide, tirzepatide, and retatrutide, you do not have to sort through it alone. Schedule a complimentary consultation with Healthy Living Medical at 4112 McKnight Rd, Texarkana, TX 75503, or call (903) 716-5925. We serve patients across Texarkana, Texas and Arkansas.

This article is for educational purposes and is not medical advice. Talk with a licensed provider about whether any medication is appropriate for you.