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PCOS Philippines

PCOS (now called PMOS) symptom: Neck and underarms

Dark patches on the neck or underarms with PCOS: what they mean

Pangingitim ng leeg o kili-kili. Darker, velvety skin on the neck, underarms or groin.

Editorially reviewed on October 29, 2026. [TODO: medical reviewer] How we review

Quick answer

Dark, velvety skin on the neck, underarms or groin is called acanthosis nigricans. In PCOS (now called PMOS) it is a skin sign of insulin resistance, not a hygiene problem.

It is a reason to ask your doctor for a 75 g OGTT. Improving insulin resistance, through movement, healthy eating and sometimes metformin, often helps the skin over time.

Bakit nangingitim ang leeg at kili-kili ko?

When your body makes a lot of insulin to overcome insulin resistance, that insulin also acts on skin cells. In skin folds like the back of the neck, the underarms and the groin, the skin cells grow faster and the skin becomes thicker, darker and velvety.

Many Filipinas try whitening products or scrubbing harder, thinking it is dirt or sun. It is neither. Scrubbing can irritate the skin and make it look worse. The patch is a message from your metabolism.

Because it is linked to insulin, acanthosis nigricans is one of the visible clues that the "metabolic" part of PMOS is active for you, and that your blood sugar deserves a proper check.

How common is it? A visible sign of insulin resistance, which is central for many people with PMOS.

Is it PCOS or something else?

Darker skin in folds has a few possible causes. A doctor should look at it:

  • Insulin resistance without PCOS: Acanthosis can appear with prediabetes or type 2 diabetes in anyone.
  • Friction and irritation: Rubbing from clothes or scrubbing can darken skin, but usually without the velvety texture.
  • Other causes: Some medicines and, rarely, other conditions can cause it. Sudden, widespread patches should be checked promptly.

A single symptom does not mean you have PCOS. Doctors diagnose it when you have two of three features (irregular ovulation, high androgens, and polycystic ovaries or a high AMH in adults), after ruling out thyroid, prolactin and other causes. The free self-check shows which features you may have.

What helps

Treat the cause, and the skin often follows slowly:

  • Ask for a 75 g OGTTStrong evidenceThe most accurate glucose test in PCOS (Rec 1.9.9), recommended at diagnosis and every 1 to 3 years. Listed in PhilHealth Konsulta.OGTT 75 g, HP Plus Alabang: ₱500 per testLearn more
  • Movement you enjoy, any amountModerate evidenceActivity improves insulin sensitivity at any weight. No type of exercise is better than another (Rec 3.3.1).Learn more
  • Metformin, if your doctor finds a problemModerate evidenceConsidered in adults with BMI 25 or higher and preferred for metabolic goals (Rec 4.3.1, 4.4.2). Prescription only.Metformin 500 mg generic (Diamet, TGP): ₱2 per tabletLearn more
  • Gentle skin careLimited evidenceStop harsh scrubbing. A dermatologist can suggest topical options for the texture and colour once the cause is addressed.

Prices checked October 2026. Prices at Philippine drugstores and labs change often; confirm before you go.

Evidence levels follow the 2023 International Guideline. Prescription medicines need a doctor; we never sell them.

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

When to see a doctor

  • Any new dark, velvety patch on your neck, underarms or groin.
  • Dark patches together with irregular periods, cravings or a family history of diabetes.
  • Patches that appear suddenly or spread quickly.

An OB-GYN is the usual first stop. A consult at Kindred costs ₱850 per consult, and government hospitals cost less. See what a PCOS check-up costs and which tests to ask for.

Example

“I thought my neck was just dirty.”

  • 75 g OGTT
  • HbA1c
  • Movement and metformin

Next steps

See all symptoms on the symptoms hub or the Symptom Map.

Frequently asked questions

Mawawala ba ang pangingitim ng leeg?

It often fades slowly when insulin resistance improves, over months. Scrubbing or whitening products do not treat the cause.

Is acanthosis nigricans dangerous?

The skin itself is harmless, but it signals insulin resistance, which raises the risk of type 2 diabetes. That is why it is worth a glucose test.

Which test should I ask for?

A 75 g OGTT is the most accurate glucose test in PCOS. Your doctor may add HbA1c and a lipid profile.

Is PMOS the same as PCOS?

Yes. PMOS (polyendocrine metabolic ovarian syndrome) is the new name for PCOS, announced in The Lancet on 12 May 2026. It is the same condition with the same diagnosis and the same treatments. Both names will be used until the 2028 International Guideline update.

Sources

  1. Recommendations from the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. Teede HJ et al., Fertility and Sterility (co-publication), 2023.
  2. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. Teede HJ, Bahri Khomami M, Morman R, et al. The Lancet. DOI 10.1016/S0140-6736(26)00717-8, 12 May 2026.
  3. PhilHealth Circular 2024-0013, Annex B: Konsulta Benefit Table. PhilHealth, 2024.
  4. Diabetes medicine prices in the Philippines. ClinicFinderPH, August 2026.