Semaglutide: Uses, Weight Loss, How to Take & Side Effects

Updated in December 2023

Semaglutide is an antidiabetic that is indicated for the treatment of type 2 diabetes. It works by stimulating insulin production in the pancreas and decreasing glucagon production, which helps to reduce blood glucose levels in the blood. It is most effective when combined with a healthy diet and regular exercise.

This medication is also used for weight loss. It promotes satiety and decreases the sensation of hunger. As a result, weight loss occurs due to a reduction of overall daily calorie intake.

Semaglutide can be obtained with a prescription at pharmacies as an injectable (also known as Ozempic) or as pills (also known as Rybelsus). It should be used as prescribed by your family doctor or endocrinologist. 

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Common uses

Semaglutide is indicated for the treatment of:

  • Uncontrolled type 2 diabetes mellitus, when diet, physical exercise and/or the use of other antidiabetics alone are not enough to control blood sugar levels;
  • Obesity in adults with a BMI greater than 30 kg/m2;
  • Excess weight in adults with a BMI greater than 27 kg/m2, in addition to a chronic disease such as high blood pressure, diabetes mellitus, dyslipidemia or high cholesterol;
  • Childhood obesity, in adolescents over 12 years of age, with body weight greater than 60 kg, used in association with a low-calorie diet and increased physical exercise.

This medicine is a synthetic hormone, similar to glucagon which produced naturally by the body. It stimulates insulin production, which regulates blood sugar levels, when associated with a balanced diet and physical exercise.

Semaglutide for the treatment of diabetes can be used alone or in combination with other antidiabetic medications, such as metformin, for example, as prescribed by endocrinologist.

Semaglutide for weight loss

Semaglutide is a medication that works by stimulating insulin production in the pancreas. This regulates blood sugar levels and satiety, which leads to less desire to eat and possible weight loss. 

People with diabetes that use semaglutide will notice more normal blood sugar levels, as this medication helps with sugar to be easily absorbed into the cells. Overtime, reduced blood sugars leads to a decreased accumulation of fat. 

In 2021, injectable semaglutide was approved for chronic weight management by the FDA. It is indicated for patients with a BMI over 30, and in patients with a BMI over 27 plus a weight-related illness, like high blood pressure, type 2 diabetes, or high cholesterol. After several clinical reviews, the FDA deemed it is a safe, effective option when used in combination with a reduced calorie diet and regular exercise. 

Semaglutide for weight loss has also been approved by Health Canada and the MHRA in England. 

How to take

The way to take semaglutide varies depending on the type the doctor prescribes you:

1. Rybelsus (semglutide tablets)

Semaglutide tablets, known as Rybelsus, can be found in doses of 3 mg, 7 mg or 14 mg. They can be used alone or combined with other medications to manage diabetes, as prescribed by a doctor.

The tablets should be taken whole with a glass of water, on an empty stomach, preferably before breakfast. You should wait at least 30 minutes before having the first meal of the day or before taking other medications.

The normally recommended starting dose for adults is one 3 mg tablet per day, for 30 consecutive days. After the first month, the dose can be increased by the doctor to one 7 mg tablet per day. If necessary, after 30 days, the doctor may recommend taking one 14 mg per day.

The maximum daily dose of semaglutide should not exceed 14 mg and should be taken as prescribed.

2. Ozempic (Semaglutide injectable pen)

Semaglutide in the form of an injectable pen, known as Ozempic is injected into the subcutaneous layer of the skin (under the skin), either in the belly, thigh or upper arm. 

The normally recommended initial dose for adults is one injection of 0.25 mg, once a week. After four weeks, the dose is usually increased by the doctor to 0.5 mg once a week. If blood glucose is not well controlled, the doctor may increase the dose of the medication to 1 mg, once a week.

3. Wegovy (Semaglutide injectable pen)

Wegovy contains semaglutide in the form of an injectable pen. It is available in doses of 0.25 mg, 0.5 mg, 1.0 mg, 1.7 mg and 2.4 mg, and is applied in the subcutaneous layer of skin in the belly, thigh or upper arm.

Semaglutide for the treatment of overweight or obese adults, or adolescents over 12 years of age and weighing more than 60 kg, should be injected once a week, starting with smaller doses and gradually increased each month by the endocrinologist. The recommended dosing is outlined below:

Month of treatment

Recommended weekly dose

First week (Weeks 1 to 4)

One 0.25 mg injection, once per week

Second week (Weeks 5 to 8)

One 0.5 mg injection, once per week

Third week (Weeks 9 to 12)

One 1.0 mg injection, once per week

Fourth month (Weeks 13 to 16)

One 1.7 mg injection, once per week

Fifth month (Weeks 17 and ongoing)

One 2.4 mg injection, once per week

These doses should only be increased as prescribed by an endocrinologist, and will depend on the response to treatment and assessment of side effects.

You should choose a day of the week and a time for injection, so that the dose is always injected on the same day of the week and at the same time.

If you forget to inject the weekly dose on the correct day and time, you can inject it as soon as you remember up to a maximum of 5 days of forgetting. After 5 days, or if the next scheduled dose is in less than 48 hours, you should skip the missed dose and continue the weekly schedule as scheduled.

For example, if the person applies the weekly dose on Monday at 10 am, and forgot to apply it on that day, they can apply it at the latest on Saturday at 10 am, as long as they are at least 48 hours away from the dose scheduled for Monday.

Adolescents over 12 years of age should have regular medical monitoring to assess the effectiveness of the treatment. These patients will usually be advised to continues semaglutide use if there is a loss of at least 5% of BMI, after 12 weeks of treatment with a dose of 2.4 mg or the maximum tolerated dose.

If this result has not been achieved, the doctor should reevaluate treatment.

Possible side effects

The most common side effects of using semaglutide are:

  • Nausea or vomiting
  • Stomach ache
  • Heartburn or poor digestion
  • Diarrhea or constipation
  • Excess intestinal gas
  • Frequent burping
  • Loss of appetite
  • Difficulty swallowing
  • Hypoglycemia
  • Anxiety or depression
  • Headache
  • Dizziness
  • Tiredness

It is important to seek immediate medical attention or to proceed to the nearest emergency room if you experience symptoms such as decreased urine output, severe nausea and vomiting that does not improve, severe stomach or abdominal pain, blurred vision, hoarseness, shortness of breath, heartbeat rapid heartbeat, yellowing of the skin or eyes, swelling, and watery or bloody diarrhea.

In addition, the doctor should be informed if you notice changes in mood or behavior, depression, anxiety, talks or thinks about hurting themselves or thoughts about suicide.

Semaglutide can also cause less common effects, such as inflammation of the pancreas (pancreatitis), gallstones, changes in the taste of food and stomach paralysis (gastroparesis).

Injections may cause side effects may appear at the injection site, such as pain, itching, irritation, lesions and purple spots near the place semaglutide was applied.

Ozempic face

Ozempic face is a term that has been popularly used to indicate the changes that rapid weight loss can cause to the face, such as facial aging or sagging.

However, this term is not a medical term, as any procedure that leads to rapid weight loss, such as bariatric surgery, can have the same effect on the face. Furthermore, the term Ozempic face appears to reinforce the stigma surrounding the treatment of obesity, which is why using this term is not recommended.

Contraindications for use

Semaglutide should not be used by patients who are allergic to any of the formula's components nor by people with type 1 diabetes or diabetic ketoacidosis.

This medicine should also not be used by children and adolescents under 18 years of age, nor by pregnant or breastfeeding women.

In addition, people with kidney or pancreatic disease, people with stomach problems such as hiatal hernias or GERD, or people who are using other medication  should inform their doctor about these conditions before starting semaglutide.

Care during treatment

Be sure to keep the following considerations in mind when taking semaglutide:

  • Do not use semaglutide unless prescribed by your doctor.
  • Take or inject semaglutide at the right times, as advised by your doctor.
  • Do not increase the dose on your own, and only increase as prescribed.
  • Inform your doctor of all medications you use, including vitamins or dietary supplements, as semaglutide may interfere with the absorption of these medications.
  • Follow the diet and exercise advice recommended by your doctor.
  • Eat in small quantities with short intervals in between.
  • Drink at least 2 L of water per day, to keep the body hydrated, and to avoid dehydration in the case of diarrhea or vomiting.
  • Avoid very hot foods, as the steam from the food can cause nausea and vomiting.
  • Avoid consuming alcoholic beverages.
  • Tell your doctor immediately if you become pregnant during treatment.

In addition, medical follow-ups should be carried out regularly. You should communicate any side effects to your doctor so that treatment can be reevaluated. 

Read more about the weight loss diet that you can maintain when taking semaglutide.