Comet 500 is an oral antihyperglycemic medication containing Metformin Hydrochloride, which belongs to the biguanide class of drugs. It is the first-line treatment for Type 2 diabetes mellitus, particularly in patients who are overweight. Unlike some other diabetes medications, Comet 500 works by improving the way the body handles insulin without increasing insulin production, which minimizes the risk of low blood sugar. Produced by Square Pharmaceuticals PLC, here is the comprehensive guide for 2026.
What is Comet 500 Used For?
Comet 500 mg is primarily prescribed for:
-
Type 2 Diabetes Management: Used as monotherapy or in combination with other oral antidiabetics or insulin when diet and exercise alone are insufficient.
-
PCOS Treatment: Often used off-label to manage Polycystic Ovary Syndrome (PCOS) by improving insulin sensitivity and restoring regular ovulation.
-
Gestational Diabetes: Sometimes used during pregnancy under strict medical supervision to control blood sugar levels.
-
Weight Management: While not a weight-loss drug, it is often preferred for overweight diabetic patients as it does not cause weight gain and may assist in modest weight reduction.
Dosage
The dosage of Comet 500 must be individualized based on the patient’s blood glucose levels and tolerance.
-
Adults: The usual starting dose is 500 mg twice daily or 850 mg once daily, taken during or after meals.
-
Children (10+ years): Typically starts at 500 mg twice daily.
-
Maximum Dose: The maximum recommended daily dose is 2000 mg (for children and adults) or up to 2550 mg for adults requiring intensive control, divided into 2 or 3 doses.
-
Administration: It is vital to take Comet with meals to reduce gastrointestinal side effects.
Common Side Effects
Gastrointestinal symptoms are the most common side effects, occurring in up to 30% of patients. These include:
-
Nausea and vomiting
-
Diarrhea or loose stools
-
Stomach ache or abdominal discomfort
-
Metallic taste in the mouth
-
Loss of appetite
2026 Safety & Peer Review Update
Recent clinical reviews in The Lancet Diabetes & Endocrinology (2025) reaffirm that long-term use of Metformin can lead to a Vitamin B12 deficiency. It is now recommended that patients on Metformin for more than four years undergo annual B12 screening. Furthermore, the risk of Lactic Acidosis remains extremely rare ($<0.03$ cases per 1,000 patient-years) and is primarily a concern for those with severe kidney or liver impairment.
Important Warnings & Precautions
-
Kidney Health: Do not use if your eGFR is below $30\text{ mL/min}/1.73\text{m}^2$.
-
Alcohol Consumption: Avoid excessive alcohol, as it increases the risk of lactic acidosis.
-
Surgery & Imaging: Temporarily stop Comet 48 hours before surgery or any imaging procedure involving iodinated contrast dye.
-
Vitamin B12: Long-term therapy may require B12 supplementation to prevent megaloblastic anemia.
Comet 500 vs. Comet XR 500: Key Differences and Usage
While both contain Metformin, the release mechanism significantly affects how the medication is tolerated.
| Feature | Comet 500 (Immediate Release) | Comet XR 500 (Extended Release) |
| Release Type | Instant release | Slow, gradual release |
| Frequency | 2–3 times daily | Usually once daily (Evening) |
| GI Side Effects | More common (Nausea/Diarrhea) | Significantly lower |
| Dosage Strategy | Taken with every major meal | Taken once with evening meal |
| Unit Price | ৳5.00 | ৳6.00 |
Comet 500 Price in Bangladesh (January 2026 Update)
Updated pricing for Comet and its popular variations by Square Pharmaceuticals PLC.
| Product Name | Strength | Unit Price (BDT) | Strip Price (10 Tablets) |
| Comet 500 | 500 mg | ৳5.00 | ৳50.00 |
| Comet 850 | 850 mg | ৳6.02 | ৳60.20 |
| Comet XR 500 | 500 mg | ৳6.02 | ৳60.20 |
| Comet XR 1GM | 1000 mg | ৳9.03 | ৳90.30 |
Comet 500 Alternative Brands & Prices
Metformin is highly accessible in Bangladesh. Below are top alternatives for the 500 mg strength as of January 2026.
| Brand Name | Company Name | Price per Unit (BDT) |
| Informet 500 | Beximco Pharmaceuticals | ৳3.00 |
| Glunor 500 | Eskayef (SK+F) | ৳4.00 |
| Nobesit 500 | Incepta Pharmaceuticals | ৳4.00 |
| Glucomet 500 | Aristopharma Ltd. | ৳4.00 |
| Daomin 500 | ACME Laboratories Ltd. | ৳4.00 |
| Metfo 500 | Pacific Pharmaceuticals | ৳4.00 |
| Glymin 500 | Healthcare Pharmaceuticals | ৳4.00 |
| Bigmet 500 | Renata Limited | ৳4.00 |
| Metsa 500 | Sanofi Bangladesh Ltd. | ৳3.01 |
| D-Met 500 | Ad-din Pharmaceuticals | ৳4.00 |
Frequently Asked Questions (FAQ) About Comet 500
Q: What is the Comet 500 mg price in Bangladesh?
As of January 2026, the retail price for Comet 500 is ৳5.00 per tablet. A full strip of 10 tablets costs ৳50.00.
Q: What are the Comet 500 side effects?
The most common side effects are stomach-related, including nausea, diarrhea, vomiting, and abdominal pain. A metallic taste in the mouth is also frequently reported.
Q: What is Comet 500 used for?
It is primarily used to control high blood sugar in patients with Type 2 diabetes. It is also commonly used to treat insulin resistance in women with PCOS.
Q: What is the recommended Comet 500 dose?
The usual starting dose is one 500 mg tablet twice daily with meals. Your doctor may gradually increase this based on your blood sugar levels.
Q: Is Comet 500 good for a cough?
No, Comet 500 is a diabetes medication and has no effect on coughs, colds, or respiratory infections.
Q: What does Comet do?
Comet works by reducing the amount of glucose produced by the liver, decreasing glucose absorption in the intestines, and increasing the body’s sensitivity to insulin.
Q: Does Comet 500 make you sleepy?
No, Comet 500 does not typically cause drowsiness. However, if your blood sugar becomes too low (hypoglycemia) due to other factors, you may feel tired or dizzy.
Q: Is Comet 500 mg high risk?
It is considered one of the safest first-line treatments for diabetes. However, it carries a rare risk of lactic acidosis for patients with severe kidney or liver disease.
Q: Are there any alternatives to Comet 500 in Bangladesh?
Yes, several high-quality alternatives exist, such as Informet (Beximco), Glunor (SK+F), and Nobesit (Incepta).
Q: Is Comet 500 safe during pregnancy?
Yes, Metformin (Comet) is generally considered safe during pregnancy (Category B) and is often used to manage gestational diabetes. While it crosses the placenta, research shows no increased risk of birth defects. Always consult your doctor before use.
Disclaimer: This is educational information only (updated January 2026). Not a substitute for professional medical advice. Always consult a qualified physician before starting/stopping any medication.
