How do GLP-1 agonists help with weight loss?

All these drugs are what are known as GLP-1 agonists. While originally created for type 2 diabetes, they have been highly effective for weight loss. Without delving into the exact mechanisms, they basically work by mimicking a hormone that makes you feel full, slows down how fast your stomach empties, and helps control blood sugar levels. This means you feel fuller for longer, eat less, and have fewer cravings for sugary foods, leading to weight loss.

Key Differences

When comparing these medications, we’ll focus on their effectiveness for weight loss and method & frequency of administration.

Effectiveness for Weight Loss

Ozempic (Semaglutide): While primarily for type 2 diabetes, it has demonstrated substantial weight loss benefits, though typically less than Wegovy due to its lower dosing for diabetes management.

Wegovy (Semaglutide): Shown to be highly effective for weight loss in clinical trials, with participants losing up to 10-15% of their body weight on average.

Mounjaro (Tirzepatide): Offers promising results, potentially more effective than GLP-1 agonists alone due to its dual mechanism of action. Early studies suggest significant weight loss, potentially surpassing Wegovy in some cases.

Saxenda (Liraglutide): Effective for weight loss, with average losses of around 5-10% of body weight, though generally less effective than higher-dose semaglutide (Wegovy) or tirzepatide (Mounjaro).

Rybelsus (Semaglutide): The oral form of semaglutide shows effectiveness similar to Ozempic, but potentially less convenient and slightly less effective for weight loss due to the nature of oral absorption.

Administration & Frequency

Ozempic: Given as a weekly subcutaneous injection. Designed for diabetes treatment but used off-label for weight loss at doses lower than Wegovy.

Wegovy: Administered via subcutaneous injection once a week. Its high dose of semaglutide specifically targets weight loss.

Mounjaro: Also a weekly subcutaneous injection. Its unique action on both GLP-1 and GIP receptors makes it a novel treatment for weight management.

Saxenda: Requires a daily subcutaneous injection. While effective, the daily administration may be less convenient for some people compared to weekly options.

Rybelsus: The only one in pill form, taken orally once daily. While convenient, the effectiveness for weight loss might be slightly reduced compared to injectable forms.

How much weight can I expect to lose in a month?

The amount of weight one can expect to lose in a month can vary significantly depending on several factors including starting weight, diet, exercise habits, overall lifestyle, and whether any weight loss medications are used.

As a baseline, with diet and exercise alone, a common guideline for safe and sustainable weight loss is 1-2 pounds per week. This translates to about 4-8 pounds in a month. Achieving this typically involves creating a calorie deficit of 500 to 1,000 calories per day. With Medication, the amount of weight loss can potentially increase depending on the medication and how an individual responds to it. For example:

• Wegovy (Semaglutide): Clinical trials have shown an average weight loss of about 10-15% of body weight over a year. In the first month, weight loss might be more rapid as the body adjusts. For example, if you weigh 200 lbs, you can expect to lose up to 20 lbs to 30 lbs.
• Mounjaro (Tirzepatide): Early results suggest that it might be even more effective than Wegovy, with similar or slightly higher initial monthly weight loss expected (15-20% of body weight). For example, if you weigh 200 lbs, you can expect to lose up to 30 lbs to 40lbs.
• Ozempic, Saxenda, and Rybelsus: While effective, the expected weight loss in the first month would likely align more closely with the general guideline of 1-2 pounds per week, possibly slightly higher depending on individual factors (5-10% of body weight). For example, if you weigh 200 lbs, you can expect to lose up to 10lbs to 20lbs.

It’s important to note that weight loss is often more substantial at the beginning of a diet or medication regimen, partly due to the loss of water weight. Sustainable weight loss is a gradual process, emphasizing the importance of patience and consistency.

Will I gain the weight back if I stop taking the medication?

If you stop taking the medication, you might gain the weight back, especially if you haven't changed your eating and exercise habits for the long term. A study conducted in 2022 found that people regained two-thirds of the weight lost after they stopped taking Ozempic for a year. Here are the main reasons why this can happen:

• Feeling Hungrier: These medicines often help you feel less hungry. When you stop taking them, you might feel hungrier than before, which can lead to eating more.
• Change in Metabolism: Some of these medicines might also help your body burn calories a bit faster. Without the medicine, your body might not burn calories as quickly, making it easier to gain weight.
• Habits Matter: Losing weight and keeping it off usually means eating healthier and moving more. If you relied only on the medicine without changing your habits, you might find it hard to keep the weight off once you stop the medication.

Side Effects

While some side effects are common across these medications due to their similar mechanisms of action, there are differences worth noting.

Common Side Effects Across Most GLP-1 Agonists:

• Nausea and Vomiting: A common side effect, especially when beginning treatment.
• Diarrhea: Some people may experience gastrointestinal disturbances.
• Constipation: Changes in bowel habits can occur.
• Headache: Some individuals report headaches, especially in the initial stages of treatment.
• Appetite Changes: Decreased appetite is a common and intended effect, but for some, it can be uncomfortable.

Specific Medications:

Ozempic and Rybelsus (Both contain Semaglutide): Similar side effects, including gastrointestinal issues. Rybelsus being an oral medication, may have slightly different absorption dynamics which can influence the side effect profile, potentially offering a slightly different experience in gastrointestinal symptoms compared to injectable Ozempic.

Wegovy (Higher dose Semaglutide): Shares side effects with Ozempic and Rybelsus but may have a higher incidence of gastrointestinal side effects due to its higher dose. This can include more pronounced nausea, vomiting, and diarrhea.

Mounjaro (Tirzepatide): Along with common GLP-1 related side effects, Mounjaro, due to its dual mechanism (GLP-1 and GIP receptor activation), might present a unique side effect profile. Early data suggest a similar range of gastrointestinal side effects, potentially with variations in intensity.

Saxenda (Liraglutide): Shares many common side effects with the other medications listed, with a focus on gastrointestinal disturbances. As a daily injection, the frequency of administration could potentially influence side effect perceptions and management.

Important Considerations:

• Severity and Duration: The intensity and duration of side effects can vary. Many side effects, particularly gastrointestinal ones, tend to decrease in severity over time as the body adjusts to the medication.
• Injection Site Reactions: For injectable medications (Ozempic, Wegovy, Mounjaro, Saxenda), there can be reactions at the injection site, such as redness or irritation.
• Risk of Thyroid C-cell Tumors: Medications like liraglutide (Saxenda) carry a warning about a potential risk for thyroid C-cell tumors, based on animal studies.

Cost & Insurance

The cost of each medication will vary slightly depending on your insurance plan and the pharmacy you choose. The cost of each without insurance is approximately:

• Ozempic: $220 - $265 per month, $3000 - $3300 per year
• Rybselsus: $245 - $275 per month, $3000 - $3300 per year
• Mounjaro: $380 - $480 per month, $4500 - $5800 per year
• Saxenda: $250 - $330 per month, $3300 - $4300 per year
• Wegovy: Not available until mid 2024

See here for a more detailed list of pricing by dosage and duration.

While provincial insurance such as OHIP does not currently cover the cost of medication, some private insurance plans such as those through your employer may. Here are some steps you can take to find out if your specific plan covers these medications:

• Review Your Insurance Policy: Start by looking at the details of your health insurance policy. Most insurers provide a list of covered medications, also known as a formulary, which you can often find on their website or by calling customer service.
• Contact Your Insurance Provider: To get the most accurate information, call your insurance provider directly. Ask them about coverage for the specific weight loss medication you are considering, such as semaglutide, tirzepatide, or liraglutide. Be sure to inquire about any conditions or criteria that must be met for coverage.

Some insurance plans have specific rules about what medications they will cover based on the conditions for which the drugs were originally approved (On-label vs. Off-label Use) by regulatory agencies, such as Health Canada.

Here's a breakdown of what that means:

• On-label use refers to the use of a medication for conditions for which it was specifically approved. These are the uses that have been thoroughly reviewed and approved by regulatory bodies after clinical trials demonstrate the drug's safety and effectiveness for those conditions. Saxenda (Liraglutide) and Wegovy (semaglutide) are both officially approved for weight loss
• Off-label use involves prescribing medications for conditions other than those for which it was originally approved. This practice is legal and common, often based on emerging research or clinical experience suggesting the medication's effectiveness for other conditions. However, insurance companies may not always cover off-label uses because these uses lack formal regulatory approval. Mounjaro (Tirzepatide) and Ozempic (semaglutide) are not officially approved for weight loss, but are approved for diabetes

Some insurance providers will only reimburse or cover the cost of the medication if you meet the 'on-label' prescribing criteria. This means you may require a diagnosis of diabetes to qualify for Ozempic, or a diagnosis of obesity to qualify for Wegovy. A physician during your consult can help you select the appropriate medication depending on your coverage.

Getting a Prescription in Canada

At TeleTest, we offer same-day appointments for both new prescriptions and renewals. To qualify, your BMI either needs to be greater than 30 or greater than 27 if you have one of the following obesity-related health conditions:

• High Blood Pressure
• High Cholesterol
• Diabetes
• Polycystic Ovarian Syndrome (PCOS)
• Sleep Apnea
• Fatty Liver Disease

Assuming you meet the criteria, getting a prescription is relatively straightforward:

1. Complete a brief intake form and select your preferred medication (if you are not sure which one is right for you, a doctor during your consultation can help you decide.)
2. Complete a messaging consultation (should take less than 3 minutes) to obtain a requisition for blood work.
3. Once we have your bloodwork, there will be a follow up consultation where the doctor will address any questions, side effects, and issue a 3-month prescription.

Since we offer same-day appointments and you can go to the lab right after the initial consult, you can receive your prescription in as little as 24 hours.

Can I switch prescriptions?

Yes, if your original prescription is through another provider or you would like to switch to a different medication, blood work is not required. We simply need proof of your current prescription which can be any of the following:

• A pharmacy receipt
• Prescription box with your health details
• Digital copy of your prescription
• Photocopy of a prior prescription

Which one is right for me?

Effectiveness: Wegovy, with high-dose semaglutide, and Mounjaro (tirzepatide) have shown significant effectiveness in weight loss, potentially more so than Ozempic, Rybelsus, and Saxenda in respective settings.

Administration: Saxenda requires daily injections, while Ozempic, Wegovy, and Mounjaro are weekly. Rybelsus is the only oral option.

Primary Use: Saxenda and Wegovy are specifically approved for weight management, whereas Ozempic and Rybelsus are primarily for diabetes management but can assist in weight loss. Mounjaro is a newer option that's gaining attention for its weight loss benefits beyond its diabetes treatment capability.

Choosing the appropriate weight loss medication is a decision that hinges on several factors, including cost and insurance coverage, the method of administration, and the frequency of doses. Cost and insurance coverage are often the deciding factors for many, as these determine the financial feasibility of continuing treatment. The method of administration, whether it be injections or oral medications, can influence a patient's willingness and ability to adhere to the treatment regimen. Finally, the frequency of doses, ranging from daily to weekly, plays a significant role in fitting the medication into the patient's lifestyle and maintaining consistent use. Each of these factors carries substantial weight in the decision-making process, hence the importance of a personalized approach in selecting the right weight loss medication for each individual.

See our FAQ for more information on GLP-1 agonists.

Disclaimer: This blog post is intended for educational purposes only and should not be taken as medical advice. Always consult your healthcare provider for personal health concerns.