Metformin can be delivered to your home via online consultation.
3,500 yen (tax included, shipping and consultation fees included) / Consultations available daily from 9:00 to 22:00, with same-day shipping possible.
What is Metformin? | Why a staple diabetes drug is gaining attention for weight management
Metformin (a biguanide drug) is a medication that has been used worldwide for over 60 years as a first-line treatment for type 2 diabetes. Its long history of use means there is a wealth of accumulated data on side effects and precautions.
Among diabetes medications, it is known for not causing weight gain. Furthermore, a large-scale study targeting individuals in the pre-diabetic stage confirmed a modest weight reduction. This result has led to its use for weight management purposes.
Please note that in Japan, metformin is approved for the treatment of type 2 diabetes. Prescribing it for weight management is considered off-label use (private medical care) (details to follow).
How Metformin Works
Metformin works in several ways to lower blood sugar.
| Action | Details |
|---|---|
| Suppresses glucose production in the liver | Reduces the amount of new glucose produced by the liver (gluconeogenesis), moderating the rise in blood sugar during fasting. |
| Improves insulin sensitivity | Tissues like muscles become more responsive to insulin, allowing blood glucose to be used more readily. Since it does not directly increase insulin secretion, it is less likely to cause hypoglycemia when used alone. |
| Suppresses glucose absorption from the intestines | Reduces the amount of glucose absorbed from food. |
| Promotes GLP-1 secretion | It has also been reported to act on the intestines, increasing the secretion of GLP-1, a hormone involved in appetite and satiety. |
The stabilization of blood sugar and insulin levels helps to reduce cravings for snacks and sweets, which is another reason it is used for weight management.
How much weight can you lose? A guide to effectiveness
Metformin's weight loss effect is not "dramatic" but rather "gradual and sustainable." The most referenced large-scale study (Diabetes Prevention Program / DPP) reported the following results for pre-diabetic individuals:
| Condition | Result |
|---|---|
| 1,700mg daily for an average of 2.8 years | Average weight loss of approx. 2.1kg (approx. 0.1kg for placebo group) |
| Diabetes onset during the same period | 31% lower compared to the placebo group |
| Follow-up (10 years) | Maintained approximately 2% weight loss. Those who consistently took the medication showed greater weight loss, averaging approximately 3.1kg. |
The key point is that the lost weight is less likely to return. However, it is not a drug that causes several kilograms of weight loss in a month when used alone. It is effective when combined with dietary and exercise changes, or when used in conjunction with other treatments such as GLP-1 drugs. Individual results may vary.
Who Metformin is suitable/unsuitable for
Suitable for
- Those who are hesitant about injections or GLP-1 and want to start with oral medication.
- Those who cannot stop snacking or eating sweets and are concerned about blood sugar fluctuations.
- Those who have been advised about their blood sugar or HbA1c in a health checkup (pre-diabetic).
- Those who want to continue treatment long-term at a lower cost.
- Those who are using GLP-1 drugs but want an additional boost.
- Those who have been told they have Polycystic Ovary Syndrome (PCOS).
May be unsuitable for
- Those who desire significant weight loss in a short period (GLP-1 drugs may be more suitable).
- Those with a history of weak digestion and prone to diarrhea.
- Those with existing kidney, liver, or heart conditions, or who are on dialysis.
- Those who consume large amounts of alcohol.
- Those who are pregnant, breastfeeding, or planning pregnancy.
Differences from other diet medications
The diet-related oral and injectable medications handled by our clinic can be organized by their mechanism of action as follows:
| Type | Mechanism of Action | Suitable for | Price |
|---|---|---|---|
| Metformin (Oral, daily) | Suppresses glucose production, improves insulin sensitivity | Those who want gradual, long-term results at a lower cost | 3,500 yen |
| SGLT2 Inhibitor (Oral, daily) | Excretes excess sugar in urine (approx. 200-400kcal per day) | Those who want to excrete sugar without strict dieting | 6,400 yen |
| Xenical (Oral, with each meal) | Suppresses fat absorption | Those who frequently eat fried or fatty foods | [To be confirmed] yen |
| Rybelsus (GLP-1 oral, daily) | Suppresses appetite, sustains satiety | Those who want to suppress appetite itself, or avoid injections | 3,500 yen |
| Mounjaro (GLP-1/GIP injection, once weekly) | Strong appetite suppression, significant weight loss | Those who want to lose a lot of weight | From 8,900 yen |
Metformin is not a "strong appetite suppressant" but rather a foundational drug that regulates sugar metabolism itself, which makes it easier to understand.
Concomitant use with GLP-1 drugs and SGLT2 inhibitors
Metformin works through a different mechanism of action than GLP-1 drugs (Mounjaro, Rybelsus, Ozempic, etc.) and SGLT2 inhibitors, so they are sometimes used in combination. In diabetes treatment, it is common to use metformin as a base and add other agents.
However, since both types of drugs can cause gastrointestinal symptoms, combination therapy should be started cautiously with small doses. Since some combinations can lead to dehydration, it is important to drink fluids frequently. The doctor will determine the suitability of concomitant use during the consultation.
Dosage and Administration Guidelines
- Timing: Take after meals. Taking it on an empty stomach can increase gastrointestinal symptoms.
- Starting out: The basic approach is to start with a small dose and gradually increase it every 1 to 2 weeks while monitoring your condition. Starting with a high dose from the beginning can lead to diarrhea and nausea, making it difficult to continue.
- If you forget a dose: Do not take two doses at once; return to your usual schedule for the next dose.
- When stopping: There are no withdrawal symptoms if you stop suddenly, but weight is likely to return if lifestyle habits remain unchanged.
Actual dosage and increase pace vary depending on body size, kidney function, and gastrointestinal condition. Please follow your doctor's instructions.
Side Effects and Management
The most common side effects are gastrointestinal symptoms when first starting the medication. These often become milder with continued use.
| Symptoms | Management Guide |
|---|---|
| Diarrhea, loose stools | Take after meals, slow down the increase in dosage. Consider reducing the dose if symptoms persist. |
| Nausea, loss of appetite | Take immediately after a meal. Restart with a small dose. |
| Abdominal bloating, abdominal pain | Often improves within a few weeks. If severe pain persists, stop taking the medication and seek medical attention. |
| Metallic taste | Often temporary, monitor condition. |
| Vitamin B12 deficiency with long-term use | Regular blood tests recommended for long-term use. |
Rare but important side effect: Lactic acidosis
Although very rare, lactic acid can accumulate in the blood and become severe. Impaired kidney function, dehydration, heavy alcohol consumption, and infections can trigger it. If you experience symptoms such as those listed below, stop taking the medication and seek medical attention immediately.
- Persistent severe nausea, vomiting, abdominal pain, diarrhea
- Weakness, lethargy, muscle pain
- Rapid or shallow breathing
- Cold hands and feet, confusion or altered consciousness
Those who cannot take it / Those who need to be careful
- Individuals with moderate to severe renal dysfunction or those on dialysis.
- Individuals with severe liver disease, or heart or lung conditions causing poor oxygen circulation.
- Individuals who are dehydrated, experiencing severe diarrhea or vomiting, have a fever, or are on an extremely restricted diet.
- Individuals who consume large amounts of alcohol.
- Before and after examinations using iodinated contrast agents (such as CT scans) – a period of discontinuation is required. Please inform us if you have such plans.
- Individuals scheduled for surgery.
- Individuals who are pregnant, breastfeeding, or may become pregnant.
- Elderly individuals (decision made cautiously based on renal function).
Please be sure to inform us of any existing medical conditions, medications, or supplements you are taking during the consultation.
Antioxidant Focus and TAME Trial
Following observational studies that showed good outcomes in individuals using metformin for diabetes, research has been conducted on its effects on age-related changes. While improvements in inflammation and metabolic markers have been reported in animal studies and small-scale human studies, the anti-aging effects in humans are not established, and it is not approved for this purpose.
Currently, a large-scale study (TAME trial: Targeting Aging with Metformin) is underway, targeting individuals aged 65-79, to investigate whether it affects the onset of heart disease, cognitive impairment, and cancer. The results are awaited. For now, please consider this a "topic under research."
Pricing and Online Prescription Process
Metformin is 3,500 yen (tax included, shipping and consultation fees included). There are no additional consultation or shipping fees. This is private medical care, so health insurance is not applicable.
| STEP | Description |
|---|---|
| 1. Order/Medical Questionnaire | Apply from the product page, answer the online medical questionnaire (a few minutes) |
| 2. Consultation | A doctor reviews the content and conducts an online consultation. Available daily from 9:00 to 22:00. |
| 3. Shipping | Once prescription is confirmed, same-day shipping is possible. Delivered to your home. |
If you wish for an in-person consultation, you can also be seen at Mona Aoyama Clinic in Minami Aoyama (open daily).
You can start today.
Information on Off-label Use and Private Medical Care
- Approval Status: Metformin is a drug approved in Japan for the treatment of type 2 diabetes. Its use for weight management or cosmetic purposes is considered off-label use.
- Procurement Channel: We use domestically approved products procured through domestic pharmaceutical wholesalers. These are not individually imported products.
- Cost: As it is off-label use, health insurance is not applicable, and the full cost is borne by the patient (private medical care).
- Risks: In cases of off-label use, the Pharmaceutical Side Effect Relief System may not cover damages if side effects occur. Please refer to the above for information on side effects.
- Effectiveness: The degree of effectiveness varies by individual, and not everyone will achieve the same results.
Consultations are also available via online medical care.
Frequently Asked Questions
Related Pages
- SGLT2 Inhibitors (Sugar Cut)
- Xenical (Fat Cut)
- Mounjaro (GLP-1/GIP Injection)
- Rybelsus・Ozempic (GLP-1)
- Bofutsushosan (Bowel Movement Improvement)
- About Online Consultation／About Pricing
References
Knowler WC, et al. Reduction in the Incidence of Type 2 Diabetes with Lifestyle Intervention or Metformin. N Engl J Med. 2002.
Diabetes Prevention Program Research Group. Long-term Safety, Tolerability, and Weight Loss Associated With Metformin in the DPPOS. Diabetes Care. 2012.
American Federation for Aging Research. TAME Trial.
