Anyone looking for a way to lose weight has probably heard the term... “Weight loss pen“ They're being sold more and more often because they're very popular in our country, both on social media and in various beauty clinics. But when it comes time to actually buy them, there are concerns that...What brands are available? Which types are good, and most importantly, are they safe? And for that reason, this article has compiled them, focusing specifically on... Approved by the Thai FDA. That's all. No counterfeit goods, no items with unknown origins. If you want to know which ones are popular and which ones are right for you, follow along!
Key points
- A weight-loss pen is... A medical device designed to resemble a pen in size and shape, used for weight control and reduction. The treatment involves injecting medication under the skin with a very small needle.
- Mounjaro The trade name of the drug is "Tirzepatide," which belongs to the dual agonist class. It mimics the action of two natural hormones: GLP-1 (Glucagon-like Peptide-1) and GIP (Glucose-dependent Insulinotropic Polypeptide). It is a novel injectable drug used for weight loss and blood sugar control.
- Wegovy The trade name for this medication is "Semaglutide." It works by mimicking the action of the hormone GLP-1 (Glucagon-Like Peptide-1), stimulating insulin secretion, inhibiting glucagon secretion, delaying gastric emptying, and stimulating fat metabolism.
- Saxenda The trade name for the drug is "Liraglutide." It mimics the action of the hormone GLP-1 (Glucagon-Like Peptide-1) through three main mechanisms: signaling the brain areas that control hunger, delaying digestion, and regulating blood sugar levels.
- Ozempic The trade name for the drug is "Semaglutide," which belongs to the same class of drugs as Wegovy and works by mimicking the action of the hormone GLP-1 (Glucagon-Like Peptide-1).
A weight-loss pen is...
A weight-loss pen is a medical device designed to resemble a pen in size and shape. It is used for injection to control and reduce weight. The treatment involves injecting medication under the skin with a very small needle.
The medications used are as follows:
- GLP-1 (Glucagon-Like Peptide-1) This is a hormone naturally secreted by the small intestine after eating. In medicine, this hormone, or substances that mimic its effects, has been developed into medications for controlling blood sugar levels and as highly effective weight-loss drugs.
- GIP, or Glucose-dependent insulinotropic polypeptide It is a hormone produced by K-cells in the upper part of the small intestine, which is released when the body consumes food, especially fats and sugars.
The results after receiving weight-loss injections include a potential weight loss of approximately 51 to 151 TP3T of initial weight within 6–12 months. However, the timeframe may vary depending on the dosage and individual body response. The injections also lead to improved body contouring, as they reduce appetite, decrease fat accumulation, and consequently a noticeable reduction in abdominal and waist circumference. Furthermore, it promotes a feeling of fullness that lasts longer, reducing cravings for sweets and fatty foods, and does not cause fatigue associated with dieting.
Mounjaro
Mounjaro The drug's trade name is "Tirzepatide," which belongs to the dual agonist group. It mimics the action of two natural hormones: GLP-1 (Glucagon-like Peptide-1) and GIP (Glucose-dependent Insulinotropic Polypeptide). It's a new injectable medication for weight loss and blood sugar control. The medication is administered subcutaneously in the abdomen, upper arm, and thigh once a week.
How the Mounjaro weight loss pen works: GLP-1 (Glucagon-like Peptide-1) slows the elimination of food from the stomach, resulting in a longer and faster feeling of fullness. It also sends signals to the brain to reduce hunger and helps control blood sugar levels. GIP (Glucose-dependent Insulinotropic Polypeptide) stimulates insulin release when blood sugar levels are high, increasing the efficiency of sugar and fat metabolism, and helping to reduce nausea often caused by GLP-1 stimulation alone.
Mounjaro's key features include hunger control, promoting a longer feeling of fullness without the need for dieting. It improves the body's metabolism, leading to weight loss of more than 15% – 20% or even more after injection, depending on factors such as the dosage and individual body composition. It is also FDA-approved in the United States for the treatment of type 2 diabetes and weight management.
Wegovy
Wegovy The drug, commercially known as "Semaglutide," works by mimicking the action of GLP-1 (Glucagon-Like Peptide-1), a hormone produced in the small intestine after eating. GLP-1 stimulates insulin secretion, which regulates blood sugar levels. Semaglutide helps to inhibit the release of glucagon, which increases blood sugar. It also slows the passage of food through the stomach, resulting in longer-lasting satiety, reduced appetite, and stimulates fat metabolism. The medication is administered subcutaneously in the abdomen, upper arms, and thighs once a week.
Wegovy's key features include appetite suppression, slowing digestion, leading to a feeling of fullness that lasts longer and results in gradual, sustained weight loss. The average weight loss is approximately 151 TP3T or more within 68 weeks. It helps control hunger, reduce cravings, and lower the risk of insulin resistance, as well as reducing the risk of cardiovascular disease.
Saxenda
Saxenda The drug, commercially known as "Liraglutide," mimics the action of the hormone GLP-1 (Glucagon-Like Peptide-1), which is released in the small intestine after eating. It works through three main mechanisms: it signals the brain's hunger control center (hypothalamus) to reduce hunger and appetite; it slows digestion, causing gastric contractions to delay gastric emptying, leading to longer satiety and a feeling of fullness; and it controls blood sugar levels, helping the pancreas release insulin appropriately when blood sugar is high. The medication is administered daily by injecting it into the subcutaneous fat layer, such as in the abdomen, thigh, or upper arm.
The key advantage of Saxenda is its flexibility in medication management. Because it requires daily injections, if severe side effects occur or medication needs to be stopped, the drug is eliminated from the body faster than with weekly injections. The precise dosage adjustment is also a plus, as the Saxenda pen is designed with an easy-to-use dial to adjust the dosage. This makes it suitable for individuals with drug sensitivities who prefer a gradual adjustment. Results such as those seen in individuals using Saxenda in conjunction with diet or exercise include an average weight loss of 81 TP3T – 91 TP3T of initial weight, improved blood sugar control, reduced risk of diabetes, and improved blood lipid levels.
Ozempic
Ozempic The drug's trade name is "Semaglutide," which belongs to the same class of medication as Wegovy. It works by mimicking the action of GLP-1 (Glucagon-Like Peptide-1), a hormone produced in the small intestine after eating. It acts through three main mechanisms: signaling the brain's hunger control center, reducing appetite and increasing satiety; slowing gastric contractions, delaying digestion; and stimulating insulin release when blood sugar levels are high, while inhibiting glucagon secretion. The medication is administered by injecting it into the subcutaneous fat layer in the abdomen, thighs, or upper arms once a week.
The key advantage of Ozempic is its excellent blood sugar control for diabetic patients, which can help reduce HbA1c by an average of 1.5% – 1.8%. It also helps reduce the risk of heart attack and stroke, and slows kidney deterioration in diabetic patients. Results include a possible weight loss of an average of 5% – 7% from initial body weight and a reduction in HbA1c by approximately 1.5% – 1.8%.
In summary, which brand of weight-loss pen is best?
| section | Mounjaro | Wegovy | Saxenda | Ozempic |
| medicine | Tirzepatide | Semaglutide | Liraglutide | Semaglutide |
| Drug group | Dual Action: GLP-1 + GIP | GLP-1 (Glucagon-like Peptide-1) | GLP-1 (Glucagon-like Peptide-1) | GLP-1 (Glucagon-like Peptide-1) |
| Mechanism of operation | It works by mimicking two hormones simultaneously (GIP and GLP-1), allowing for hunger control and improving metabolism. | It works by mimicking the hormone GLP-1, resulting in a longer feeling of fullness. | The first generation GLP-1 required daily injections. | It works by mimicking the hormone GLP-1, resulting in a longer feeling of fullness. |
| Injection frequency | Inject once a week. | Inject once a week. | Inject once a day, every day. | Inject once a week. |
| Weight loss effectiveness | Body weight can be reduced by more than 15% – 20%. | An average weight loss of approximately 15% is possible. | Average weight loss was 8% – 9%. | Average weight loss was 5% – 7%. |
| Popularity in 2026 | Number 1 (Trending) | Rank 2 (Standard) | Rank 3 (Original version) | Rank 4 |
advice : For all brands of weight-loss pens, they are classified as special controlled drugs and therefore can only be prescribed by a doctor. Do not purchase them online or from unreliable stores, as there is a risk of using counterfeit products or drugs that have deteriorated due to temperature control requirements. This can also lead to serious side effects such as pancreatitis or gallstones.
