myo-Inositol | whatsinit

About

What it is and where it shows up.

myo-Inositol is a naturally occurring polyol (sugar alcohol) with a six-carbon ring structure, synthesised by most plants and animals and found in foods such as fruits, beans, grains, nuts, and cow's milk. It is used as a nutritional supplement due to its role as a precursor to intracellular second messengers and its involvement in insulin signalling.

Safety summary

The regulatory and scientific consensus.

myo-Inositol has a well-established safety profile; normal dietary intake is estimated at 335–1,500 mg/day and no Acceptable Daily Intake (ADI) has been formally established by major regulatory bodies, reflecting its endogenous and broadly safe character. The FDA GRAS affirmation (21 CFR 184.1370) and repeated EFSA assessments have found no significant safety concerns at typical food-use levels for the general adult population. No IARC carcinogenicity classification exists, and raw materials used in its manufacture are not major allergens.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
EFSA (European Food Safety Authority) (European Union)	Approved	Authorised as a nutritional feed additive (functional group: vitamins, pro-vitamins and chemically well-defined substances having similar effect) for fish and crustaceans under Regulation (EC) No 1831/2003 (code 3a900). Renewal assessment (2025) concluded the additive remains safe for target species, consumers, and the environment. No EU-wide food additive E-number assigned for direct human food use.source
FSSAI (Food Safety and Standards Authority of India) (India)	Approved	Myo-Inositol (= meso-Inositol) is listed as a permitted ingredient in health supplements and nutraceuticals under the FSS (Health Supplements, Nutraceuticals, Food for Special Dietary Use, Food for Special Medical Purpose, Functional Food and Novel Food) Regulations. Food Business Operators must submit additional safety data when requested by the Authority.source
FDA (Food and Drug Administration) (United States)	Approved	GRAS affirmed under 21 CFR 184.1370 as a nutrient supplement. Approved for use in flavored and enhanced waters, soft drinks, fruit/vegetable juices at up to 120 mg/kg; dry milks at up to 250 mg/kg. Not intended for use in infant formula or USDA-regulated products per recent GRAS notice (GRN, Feb 2025).source

Who should approach with care

Whose guidance would steer them away.

Infants — The FDA GRAS notice explicitly excludes infant formula from the approved uses, and FSSAI nutraceutical regulations note that products for children aged 2–5 should only be given under medical advice; inositol intake in infants should be managed through specifically formulated products under medical supervision.

Diabetes — myo-Inositol acts as an insulin sensitiser and may influence insulin signalling; clinical studies are ongoing in type 2 diabetes patients to evaluate its effects, so supplemental doses should be discussed with a physician to avoid unintended glycaemic interactions.

Pregnancy — High supplemental doses of myo-Inositol are under active clinical investigation for conditions like gestational diabetes and PCOS; while typical dietary amounts are safe, supplemental use during pregnancy should be discussed with a healthcare provider.

Research citations

The sources behind this verdict.

1other. Myo-Inositol — ECHA Registered Substance Dossier (EC 201-781-2). echa.europa.eu
2FDA. GRAS Notice (GRN) for Inositol — Sichuan Bohaoda Biological Engineering Co., Ltd., 2025. fda.gov
3EFSA. Assessment of the feed additive consisting of inositol (3a900) for fish and crustaceans for the renewal of its authorisation (Zhucheng Haotian Pharm Co., Ltd.), 2025. efsa.europa.eu
4FSSAI. Direction on Health Supplements, Nutraceuticals and Special Purpose Foods — Permitted Ingredients List, 2022. fssai.gov.in
5EFSA. Safety and efficacy of inositol as nutritional additive for dogs and cats, 2016. efsa.europa.eu

Independently researched5 citations