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Sugar alcohol / signaling molecule

Myo-Inositol · Myo-Inositol

A carbocyclic sugar that acts as a second messenger in insulin and serotonin signaling pathways.

B
Evidence grade
Human RCTs, biomarker outcomes

Short answer

Solid evidence for insulin sensitivity and PCOS. Emerging evidence for mood and sleep support. Very safe.

Product and dose overview

Myo-Inositol (Myo-Inositol) is a sugar alcohol / signaling molecule with evidence grade B, meaning it is supported by human RCTs. We track 1 products containing Myo-Inositol. Typical doses range from 1000 to 1000 mg per serving. The top-ranked product scores 6.7 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $99.00 per month.

Evidence grade: B Products in database: 1 Category: Sugar alcohol / signaling molecule

Top Myo-Inositol products

ProductBrandDosePrice/mo3rd-party testedScore
AGZ: Nightly Sleep SupportAG1 (Athletic Greens)1000 mg$99.00Yes6.7

Scores are editorial judgments, not a scientific standard. See how we score.

What it is

Myo-inositol is a sugar-like molecule found in fruits and grains. It helps cells communicate, especially in insulin and serotonin pathways.

Why people take it

Higher doses (2-4g) can improve insulin sensitivity and may help with mood and sleep. Also studied for PCOS.

Our verdict

Solid evidence for insulin sensitivity and PCOS. Emerging evidence for mood and sleep support. Very safe.

Structure & class

Myo-inositol is a carbocyclic sugar that serves as a second messenger in the phosphatidylinositol signaling pathway. It mediates insulin signaling and serotonin receptor function.

Mechanism & clinical data

RCTs show improvements in insulin sensitivity markers at 2-4g/day. Meta-analyses support efficacy in PCOS. Mood studies show benefit in anxiety and OCD-spectrum conditions.

Pharmacokinetics

Not well characterized; urinary excretion within 24 hours.

Dose & forms

Trial dose
2000 mg
/ day
Range in trials
1000 to 4000 mg
/ day
Common forms
Powder, Capsule

What to watch out for

Generally very safe. May cause mild GI effects at high doses. Quality varies little between brands as it is a simple molecule.

Where this dose comes from

The trial dose above is our editorial pick from the published human trials for this ingredient. We choose the dose that the best-available studies used on the endpoint most relevant to longevity. The range shows the lowest and highest doses tested in published trials. The landmark studies below are the papers we read to set it. You can click through and check our work.

When new trials publish, our automated sweeps flag them. If a new study materially changes the dose, we update it through editorial review and record the old dose, new dose, and the triggering study in every affected product's recommendation history. The dose is never changed automatically.

Regulatory status

EUPermitted as supplement
USGRAS
UKPermitted
CAPermitted as NHP

Timeline

Regulatory events, evidence grade changes, and key research milestones for Myo-Inositol, most recent first. Studies link to the paper; regulatory entries name and link the responsible authority.

  • 2025-04 Regulatory single source
    EU Court sharpens the bar for botanical health claims
    A Court of Justice of the European Union ruling in April 2025 further tightened the requirements for how botanical ingredients (herbs, plant extracts) can be marketed with health claims in the EU, effectively removing much of the flexibility of the on-hold list.
  • 2024-06 Regulatory confirmed
    EU report identifies 117 supplement substances as potential health risks
    The HoA Working Group on Food Supplements (26 European countries) published its first report evaluating 117 substances used in food supplements. Of these, 65 were assessed as likely novel foods, 6 were already regulated, 34 had insufficient data, and 12 were prioritized for Article 8 restriction under Regulation (EC) No 1925/2006. The 12 priority substances include ashwagandha, curcumin, melatonin, piperine, St. John's wort, coumarin, p-synephrine, maca, holy basil, Melaleuca, black cohosh, and L-tryptophan. The report drew on 1,500 RASFF alerts reviewed between 2017 and mid-2022.
    Source →
  • 2006-12 Regulatory confirmed
    EU Health Claims Regulation adopted
    Regulation (EC) No 1924/2006 laid down harmonised rules for nutrition and health claims made on foods, including supplements. Only claims listed in the EU Register of authorised claims can be used. Rejected botanical claims are held in a separate on-hold list.
    Source →
  • 2001 Research milestone
    Levine et al. 2001 (Bipolar Disord)
    Myo-inositol showed efficacy as an adjunct treatment in mood disorders.
    Source →
  • 1997 Regulatory confirmed
    EU introduces the Novel Food Regulation
    Regulation (EC) No 258/97 required any food or food ingredient without a history of consumption in the EU before 15 May 1997 to be authorised before being placed on the market. This is the framework that captures NMN, spermidine as a supplement ingredient, urolithin A, and many other longevity actives.
    Source →

Landmark studies

Found in these products (1)

All products in our catalog that contain Myo-Inositol, ranked by our overall score. Ranking is editorial, never paid.

AG1 (Athletic Greens)
AGZ: Nightly Sleep Support
Adaptogen
Ingredients listed
8 ingredients listedlargest listed: Glycine 2,000 mg
Price per serving
$3.30$99.00 · 30 servings
Testing
3rd-party listed · no public lab certificate

Elemental vs compound: check label

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 6.7/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$3.96
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with drinkag1.com
Editorial guides

Buying guides and comparisons

Neighbouring molecules

Related ingredients

See all in Sugar alcohol / signaling molecule →

Molecules in the same class, plus the actives most often formulated alongside Myo-Inositol in our catalogue.

MagnesiumAstacked together in 1 productGlycineBstacked together in 1 productAshwagandhaBstacked together in 1 productL-TheanineBstacked together in 1 productSaffronBstacked together in 1 productZincAstacked together in 1 productVitamin B6 (P-5-P)Astacked together in 1 product
Product shelves
See all in Adaptogen (1)

See Myo-Inositol in context: the mechanism it acts through, the biomarker it moves, the products that dose it, and the trials that tested it.

View Myo-Inositol on the Longevity Map →

Frequently asked questions

What is Myo-Inositol?

Myo-inositol is a sugar-like molecule found in fruits and grains. It helps cells communicate, especially in insulin and serotonin pathways.

What dose of Myo-Inositol should I take?

The trial dose in published human studies is 2000 mg per day, with a range of 1000 to 4000 mg per day. Always consult a qualified clinician before starting any supplement.

Is Myo-Inositol safe?

Generally very safe. May cause mild GI effects at high doses. Quality varies little between brands as it is a simple molecule.

What is the best Myo-Inositol supplement?

We track 1 products containing Myo-Inositol. The top-ranked product scores 6.7 out of 10 on our composite scale, which evaluates dose, evidence, price, third-party testing, and transparency. See the comparison table above. Scores are editorial judgments, not a scientific standard.

What is the evidence grade for Myo-Inositol?

Myo-Inositol has evidence grade B, meaning it is supported by human RCTs. Grade A means replicated human RCTs with hard endpoints. Grade B means human RCTs with biomarker outcomes. Grade C means mixed or small human trials. See our evidence grading methodology.

Independently checked

Data verification

Evidence grade
B
Human RCTs, biomarker outcomes
Research dose
2000 mg
Products tracked
1
Updated continuously
Safety signal
Generally very safe. May cause mild GI effects at high do...

Evidence grades are reviewed when new human RCTs are published. Product counts update automatically as new products are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.