Resistant Starch
Also known as: RS2, resistant starch type 2, raw potato starch, green banana flour, high-amylose corn starch, Hi-Maize, unripe banana starch
Resistant starch is starch that escapes digestion in the small intestine and is fermented in the colon, where it is a preferred substrate for butyrate-producing bacteria. Supplement-grade material is usually type 2 resistant starch from raw potato, green banana, or high-amylose corn. Systematic reviews and meta-analyses of randomized trials, mostly in overweight adults or people with prediabetes, examined glucose and insulin outcomes at doses that often fell in the 10–40 g range. It is used in gut-health, blood-sugar-support, and satiety powders. Heat destroys type 2 resistant starch, so it must be added to cold or room-temperature products.
Research summary
Fermented in the colon to short-chain fatty acids, especially butyrate; studied for effects on insulin sensitivity, satiety hormones, and microbiota composition.
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| — | 10–20 g | — | — |
Take 10–20 g daily in cold water, smoothies, or yogurt; do not cook or add to hot liquids, which gelatinizes the starch and removes its resistance. Start at 5 g and build up over two weeks to limit gas. Trial doses ranged widely, and the raw material is typically only 50–70% resistant starch by weight, so dose by the assayed resistant-starch content.
Standardization: Resistant starch content stated (commonly 50–70% RS by weight for raw potato starch; higher for some high-amylose grades)
Source material: raw potato starch or green banana flour (RS2)
As supplied: Raw material is not 100% resistant starch; scale weight to the assayed RS percentage on the CoA.
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Bland, slightly chalky; only practical as a powder because of gram-level doses and heat sensitivity. Not suitable for gummies or hot-process formats.
Formulation notes
Heat-labile (RS2); keep out of hot-fill and baked formats. Gas and bloating during the first weeks are common.
Sources
- Metabolic Effects of Resistant Starch Type 2: A Systematic Literature Review and Meta-Analysis of Randomized Controlled Trials. (Snelson 2019)PubMed
- Effects of the resistant starch on glucose, insulin, insulin resistance, and lipid parameters in overweight or obese adults: a systematic review and meta-analysis. (Wang 2019)PubMed
- Effect of 12 wk of resistant starch supplementation on cardiometabolic risk factors in adults with prediabetes: a randomized controlled trial. (Peterson 2018)PubMed
Related ingredients
Berberine HCl
BotanicalAn isoquinoline alkaloid isolated from plants such as barberry, goldenseal, and Coptis, supplied as the hydrochloride salt.
Typical: 900–1,500 mg
Psyllium Husk
PrebioticPsyllium husk is the seed coat of Plantago ovata, a soluble, gel-forming fiber that holds many times its weight in water.
Typical: 5–10 g
Chromium Picolinate
MineralTrivalent chromium chelated with three picolinate ligands, the form used in most human trials and the best seller in blood-sugar and weight-management formulas.
Typical: 200–500 mcg
Apple Cider Vinegar Powder
OtherApple cider vinegar powder is liquid vinegar spray-dried onto a carrier such as maltodextrin or cyclodextrin so it can be used in capsules and gummies.
Typical: 500–1,500 mg
Green Coffee Bean Extract
BotanicalGreen coffee bean extract is made from unroasted coffee beans, which retain far more chlorogenic acid than roasted coffee.
Typical: 200–400 mg