Metformin for PCOS (now called PMOS): what it does, side effects and real cost

Key facts

What it is

An insulin-sensitising medicine, used for decades in type 2 diabetes

Rx or supplement

Prescription only

Typical PH cost per month

About ₱120 to ₱225 for generic; ₱1,095 for Glucophage (cost example at 2 tablets a day)

Evidence (2023 Guideline)

●●○Moderate evidence

Time to see results

About 3 to 6 months

Who prescribes

OB-GYN or endocrinologist

The monthly figures are cost examples only. Your doctor sets the real amount, and many start lower and build up.

Myth: “May metformin ba na para sa PCOS talaga?”

A Filipina on r/PCOSPhilippines asked whether a metformin sold by her OB's receptionist was “specific for PCOS” (thread). It was not. Every metformin tablet contains the same active ingredient, metformin hydrochloride, whatever the box says. Generics, RiteMed and Glucophage differ in price and in whether they are immediate or extended release, not in being made for PCOS.

That thread points to another rule worth knowing: in the Philippines, dispensing is reserved for pharmacists, and doctors and clinics may not sell medicines without FDA authorisation. You can fill your prescription at any licensed pharmacy, including for a cheaper generic if your doctor allows it.

How it works

Many women with PCOS have insulin resistanceinsulin resistance: When the body needs more insulin than usual to keep blood sugar steady.: the body needs more insulin than usual to keep blood sugar steady, and high insulin pushes the ovaries to make more androgens. Metformin lowers the liver's sugar output and helps muscles use insulin. Over months, that can support more regular cycles and better blood sugar and cholesterol results. It is not a weight-loss drug, and it works the same whatever your size. It does not change who you are or how hard you try; insulin resistance is biology, not willpower.

What the 2023 Guideline says

• Rec 4.3.1: metformin should be considered in adults with PCOS and a BMI of 25 or higher.
• Rec 4.4.2: where the goal is metabolic (blood sugar, cholesterol), metformin is preferred over the pill.
• Metformin can be used with or without a combined pill, depending on your goals. For fertility it is one option alongside clomiphene (see the fertility guide).

Whatever you take, the guideline still asks for a 75 g OGTTOGTT: Oral glucose tolerance test: you drink 75 g of glucose and blood sugar is checked over 2 hours. The most accurate glucose test in PCOS. at diagnosis and every 1 to 3 years, plus a lipid profile and yearly blood pressure. Metformin does not replace those checks.

Who it suits

• Women with signs of insulin resistance, borderline blood sugar, or a family history of diabetes
• Those whose main goal is metabolic health
• Some women who cannot take a combined pill, or who take one alongside

Weight is one factor in the guideline, not a judgment. If a doctor has made you feel that PCOS is your fault, that is weight stigma, and the guideline asks clinicians to recognise it (Rec 3.6.1, 3.6.2). You deserve a doctor who explains options calmly. Our doctor directory lists community-recommended OB-GYNs and endocrinologists.

Stomach side effects and what helps

Nausea, loose stools, cramps and a metallic taste are common in the first weeks. In a Philippine study of women with PCOS, one participant said she “completely discontinued it” because of vomiting (Garcia et al. 2025). You do not have to suffer in silence. Things doctors commonly do:

• Start with a low amount and build up slowly
• Take it with or right after meals
• Switch to an extended-release (XR or SR) form, often easier on the stomach. Metformin SR costs about ₱6.25 per tablet (about ₱375 a month in the same cost example)

Tell your doctor before stopping. Many people who quit early would have done fine with a slower start or an XR tablet.

Generic vs Glucophage: what it costs

Generic metformin is one of the cheapest medicines in PCOS care. At the brand price, the same month can cost several times more. PhilHealth Konsulta lists metformin among its benefits “as needed as part of case management”, so ask your Konsulta provider. See the full cost guide.

Safety

This guide is for information. Talk to a doctor before starting or changing any treatment.