Wegovy, Ozempic and Mounjaro: Once a Week Injections-Most Potent Weight Loss Meds

Ozempic, Mounjaro and Wegovy, the newest weight loss drugs.  with 86% of patients losing 15% or more of starting weight. Taken as a injection once a week they commonly produce more than 25% weight loss from baseline. This compares to average of 5-8% weight loss with the common diet pills and 25-30%(after a year) with baritric surgery.  They are in the family of Glucagon-like peptide 1 receptor agonists that were first developed for the treatment of diabetes. Not only are they potent blood sugar reducers but produce significant weight loss even greater than most anti-obesity medications. The mechanisms for the weight loss, often 20-25% of the starting weight include

  1. Reduction in cravings and appetite
  2. Increase in satiety
  3. Changes in food preferences- away from fatty  foods and carbohydrates
  4.  Reduced energy intake
  5. The increase in insulin produced by these three drugs regulates appetite, by sending signals to  the brain that say, “I’m full.”

Ozempic was the first of the three drugs. It was from a group of drugs called Semaglutides.  It is approved for diabetes but are used for weight loss. A stronger version of Ozempic is Wegovy.  The only difference is Wegovy doses extend to 2.4 mg per week while the original doses of Ozempic stopped at 1 mg. Recently, the FDA extended Ozempic to dose of 2.0 mg per weel. Thus Ozempic and Wegovy are used interchangeably.

Ozempic and Wegovy: The Ground Breaking Semaglutides

Ozempic, the First of the Semaglutides:

Ozempic, introduced for diabetes is the first of these potent new medications for obesity. It has been used by millions of people since it’s approval in 2018. It has a maximal approved dose of 2.0mg per week. (Wegovy is 2.4 mg/week). Like all of these drugs, each dose is given as a tiny subcutaneous injection with a pen injector once a week. To prevent GI side effects (nausea, vomiting, constipation, abdominal pain, diarrhea) the medications are started at low doses and slowly increased. Usual starting doses are 0.25 or 0.5 mg given weekly for up to 4 weeks. Dosage is increased depending on tolerability and weight loss results to higher doses of 1.7 and 2.4 mg/week..  Significant weight loss occurs beginning at 1 mg/week after 3-4 weeks when the “steady state is achieved.”

 Wegovy: Higher Dose Ozempic Approved for Weight Loss

When diabetic patients were observed to lose significant weight at a dose of 1 mg/week it was decided to increase the dose to see if greater weight loss and glycemic control would occur.  Indeed, high doss led to further reduction in HbA1c in diabetic patients and further weight loss in both diabetic and non-diabetic patients A dose of 2.4 mg produced the greatest weight loss. It has not be unusual to see weight loss of 50 to 100 lbs. in 6-8 months with this drug.  The semaglutide was  re- labeled Wegovy which was approved as a new treatment for obesity.  The weekly doses of Wegovy start at 0.25mg(similar to Ozempic) and extend to 2.4mg/wk. Taking 2.4 mg of Ozempic is identical to 2.4mg of Wegovy since they are the same chemical.

Mounjaro: Newest Medication with Greatest Weight Loss:

Mounjaro (tirzepatide) is a once-weekly inject able medication from Lilly. It is the first and only dual GIP/GLP-1 receptor agonist including insulinotropic polypeptide (GIP), and.glucagon-like peptide-1 (GLP-1). Both hormones control insulin secretion, appetite, fullness and metabolism. Greater weight loss and glucose control is seen with Mounjaro because it consists of 2 active hormones. Similar to Ozempic and Wegovy the medication  injected once a week. Doses start at 2.5 mg and rise to 15 mg per week.

What to Expect with Mounjaro, Ozempic and Wegovy:

Side effects are mostly gastrointestinal:

Only 5% of patients in the clinical studies withdrew because of side effects. This is extremely low. Most occur early and during the first few days after the injection, especially when escalating the dose. Gastrointestinal side effects are the most common with nausea being the main complaint.

Nausea: this is main side effect, not as common as you might think, usually occurs on first 1-2 days.  Lowering the dose or delaying the escalation of the dose often solves this problem.
Vomiting: usually in the beginning, associated with skipping meals, eating large meal or from eating too fast. Diarrhea: less common, possible by changes in food or effect of semaglutide on lining of GI tract.
Constipation: very common and again intermittent, may related to these drugs, often seen in rapid weight loss where there has been significant reduction in food and especially in fats and oil.
Heartburn: reflux is very common when taking these medications. It’s due to the delay in stomach emptying.
Fatigue, lack of energy: this occurs when skipping meals normally but is  increased with these drugs which are designed to lower blood sugar in diabetics. In non-diabetics there is some lowering also, but not below normal levels. A simple lowering of blood sugar can cause fatigue. This occurs mostly in late afternoon. High protein, low carb bars, shakes; cheese are used to help the symptoms. READ MORE

Weight Loss with Ozempic, Wegovy and Mounjaro

Weight loss with each of the three medications are dose related.  There is considerable variation in weight loss between individuals depending on age, gender and starting weight. Some of the subjects had diabetes which also distorts the weight loss. Average weight loss was 23% for Mounjaro and 17 to 21% for Wegovy/Ozempic. Slow downs in weight loss and actual plateaus are common and are often do to drinking large amounts of water, especially carbonated beverates with meals, eating large meals, skipping meals, and eating too fast.  Here a comparison in average weight loss and percent weight loss from baseline:

                                                                              Weight Loss with New Semaglutides:  Ozempic, Wegovy and Mounjaro

Ozempic, wegovy, Mounjaro Weight Loss with Single Injection a week new drugs

Ozempic, wegovy, Mounjaro Weight Loss

The graph above represents several studies done at different times with different criteria, dosing and length of treatment. The Wegovy study lasted 98 weeks and started with subjects weighing 15% more. The Ozempic study(gray bar) was part of the Mounjaro studies that lasted for 72 weeks and  not only included subjects with lower BMI’s but had treatment limited to maximumm of 1 mg per week. The Wegovy study(green bar)  was based on more than 1981 subjects over a much longer treatment time. The yellow bar was not actually a study, but presents the Wegovy data at 98 weeks(note Ozempic and Wegovy are the same drug)  with 2.4 mg treatment doses to compare weight loss with equivalent doses: the highest Ozempic dose(2.4 mg/wk) vs. the highest Mounjaro dose (15 mg/wk). The length of treatment cannot be

Note: The yellow Ozempic bar is interpolated data from the Wegovy study to give reader what the weight loss might have been if Ozempic was the treating medication rather than Wegovy. It suggests greater weight loss with higher doses as might be expected.


Comparison of Ozempic, Wegovy and Mounjaro with other Weight Loss Drugs

Most other weight loss drugs result in about a 5%- 9% loss of body weight. So, if you weigh 200 pounds, taking 2.4 mg of Wegovy weekly is likely to result in a 25- to 30-pound weight loss compared to a 10-pound loss for other weight loss medications that target appetite suppression, such as bupropion-naltrexone (Contrave) and phentermine-topiramate (Qsymia).  Mounjaro is even greater with weight loss of 40-50 lbs. over 72 weeks according to the study.

diet drug weight loss comparisons between fda approved medications

Warnings About These Medications                                                                                                                                  

You should not take  any of these medications if you or anyone in your family has had a rare type of thyroid cancer called Medullary thyroid carcinoma (MTC), if you have an endocrine disorder called multiple endocrine neoplasia syndrome type 2 (MEN 2) or if you are pregnant or breastfeeding. Wegovy also comes with warnings for people who have the following conditions: Pancreatitis (inflammation of the pancreas), Gallbladder issues (including gallstones), Low blood sugar,Kidney disease, Diabetic retinopathy (damage to the retina), increased heart rate,Depression.,