Where to Buy Inositol in Singapore — and How to Read the Label

If you've read that inositol is one of the best-studied supplements for PCOS — now renamed PMOS (Polyendocrine Metabolic Ovarian Syndrome) following the 2026 Lancet consensus — the next question is often a practical one: where do you buy it in Singapore, and how do you know you're choosing the right product?

Inositol is widely available in Singapore, but products differ in formulation. Two bottles at a similar price may contain different types or combinations of inositol, making it worth checking the label before you buy.

This guide covers everything you need to know before buying inositol in Singapore — from understanding different formulations and what to look for on the label to choosing a product based on current evidence rather than marketing claims.

Understanding inositol formulations

Before deciding where to buy it, take a close look at the label.

The two forms of inositol most commonly used in PMOS are myo-inositol and D-chiro-inositol. Much of the clinical evidence supporting inositol is based on formulations containing these two forms in a 40:1 ratio, which reflects the ratio found naturally in the body.

Some studies suggest that formulations containing proportionally higher amounts of D-chiro-inositol may be less favorable for ovarian function, which is why more D-chiro is not necessarily better.

When comparing products, the most useful question to ask is simple:

Does the label clearly state a 40:1 myo-inositol to D-chiro-inositol ratio, or is it a myo-inositol-only product?

Both can be reasonable choices. A myo-inositol-only formulation taken at around 2 g twice daily remains one of the most widely studied approaches.

If a product combines myo-inositol with D-chiro-inositol but does not state the ratio, it can be difficult to know whether the formulation reflects those studied in clinical research.

Where to buy it in Singapore

In Singapore, inositol is sold as a dietary supplement rather than a prescription medicine, so it is widely available over the counter.

Major pharmacy chains such as Watsons and Guardian stock inositol products from a range of supplement brands. Some products contain a 40:1 myo-inositol to D-chiro-inositol ratio, while others contain myo-inositol alone or include additional ingredients such as vitamin D or folate. Reading the label carefully will help you understand which formulation you're buying.

Buying in person has one practical advantage — you can read the label yourself before purchasing and check the formulation. Availability and pricing vary between outlets.

Prices also vary depending on the formulation, dose and whether the product comes as a powder or capsules. Rather than focusing only on the lowest price, it's worth comparing the formulation and the cost per effective daily dose.

Powder or capsules?

The choice between powder and capsules is largely one of convenience.

The most commonly studied dose is around 2 g of myo-inositol twice daily. Depending on the strength of each capsule, this may mean taking several capsules a day. Powder can make it easier to achieve the same dose and is often more economical on a cost-per-gram basis.

Capsules may be more convenient for travel or women who prefer a pre-measured dose, while powder is often chosen for long-term daily use.

What to expect from inositol

Inositol is generally well tolerated and has a favorable safety profile, but it is not a complete treatment for PMOS.

Research suggests that inositol may be particularly helpful when insulin resistance is part of the underlying picture. However, not everyone responds in the same way. If you've taken it consistently for around three months without noticing meaningful improvement, changing brands may not be the answer. Your symptoms may be influenced by other factors, and it may be worth reviewing your overall management plan rather than simply switching supplements.

It's also worth remembering that taking a supplement is only one part of managing PMOS. A medical assessment helps build a clearer picture of the metabolic and hormonal factors contributing to your symptoms. Depending on your individual situation, your doctor may consider investigations such as SHBG, fasting insulin, HOMA-IR or other metabolic and hormonal markers alongside routine assessment. Our guide to PCOS testing in Singapore explains where these assessments are available and how they fit into the broader evaluation of PMOS.

Where to start

If you're choosing an inositol supplement, start by checking whether it contains a 40:1 myo-inositol to D-chiro-inositol ratio or is a myo-inositol-only formulation. Choose a product you'll realistically take consistently, and allow around three months before deciding whether it's helping.

If you'd rather not compare labels yourself or are unsure whether inositol is the right option for you, Oestra is designed to help. Our free 5-minute assessment identifies the metabolic and hormonal patterns that may be contributing to your PMOS symptoms. Based on those results, we provide personalized lifestyle guidance and, where appropriate, evidence-based supplement recommendations tailored to your individual profile.

Whichever approach you choose, the same principle applies: choose supplements based on evidence and your individual health profile — not simply on marketing claims or packaging.

Citations

• Teede HJ, et al. Polyendocrine Metabolic Ovarian Syndrome: A Multistep Global Consensus Process. The Lancet, 2026.
• Unfer V, et al. Reviews on myo-inositol and D-chiro-inositol ratios in PMOS management, 2023–2025.