Supplements starting with O

Glossary — O

• Oak Acorn
  Seed
  Human-reviewed profile
  Oak acorn seeds are rich in polyphenols (notably gallotannins, ellagitannins, and gallic acid), complex carbohydrates, and monounsaturated f…
• Oak Galls
  Other
  Human-reviewed profile
  Oak galls contain 50-70% gallotannins and 2-4% gallic acid, which exert therapeutic effects through NF-κB inhibition, VEGF suppression, and …
• Oat Beta-Glucan
  Fiber
  Human-reviewed profile
  Oat beta-glucan is a soluble dietary fiber, primarily a mixed-linkage (1,3)(1,4)-β-D-glucan, known for its gel-forming properties. This uniq…
• Oat Beta-Glucan Prebiotic
  Fiber
  Human-reviewed profile
  Oat beta-glucan is a soluble, fermentable fiber, primarily composed of β-glucan polysaccharides, that selectively modulates gut microbiota. …
• Oat Fiber
  Fiber
  Human-reviewed profile
  Oat fiber primarily consists of insoluble dietary fibers like arabinoxylans and cellulose, along with conjugated phenolics, derived from the…
• Oat Grass
  Other
  Human-reviewed profile
  Oat grass is a nutrient-dense young shoot of the oat plant containing high concentrations of chlorophyll, antioxidants, and avenanthramides.…
• Oat Grass Juice
  Other
  Human-reviewed profile
  Oat grass juice from Avena sativa contains unique avenanthramides that enhance nitric oxide production and inhibit phosphodiesterase-4, impr…
• Oat Straw
  Other
  Human-reviewed profile
  Oat Straw supports cognitive function and nervous system relaxation primarily through its unique avenanthramides, which enhance nitric oxide…
• Oatstraw (Avena sativa)
  European
  Human-reviewed profile
  Oatstraw (Avena sativa) contains avenanthramides and flavonoids, primarily supporting anti-inflammatory and nervous system functions. Avenan…
• Oaxacan Green Corn
  Grain
  Human-reviewed profile
  Oaxacan Green Corn is rich in bioactive compounds like anthocyanins, phenolic acids, and flavonoids, which primarily exert their benefits th…
• Oca Root
  Root/Rhizome
  Human-reviewed profile
  Oca Root (Oxalis tuberosa) contains high concentrations of vitamin C (77 mg/100g) and anthocyanins that demonstrate potent antioxidant activ…
• Oca Tuber
  Root/Rhizome
  Human-reviewed profile
  Oca Tuber (Oxalis tuberosa Mol.) is a nutrient-dense Andean tuber rich in polyphenols, anthocyanins, resistant starch (2–10% wet basis), vit…
• Oca Tubers
  Root/Rhizome
  Human-reviewed profile
  Oca Tubers are rich in polyphenols, anthocyanins, and fructooligosaccharides, contributing to their beneficial health effects. These compoun…
• Ocean Grapes
  Berry
  Human-reviewed profile
  Ocean Grapes (referring to *Vitis* species) are rich in bioactive polyphenols, including anthocyanins, proanthocyanidins, and resveratrol. T…
• Ocean Grapevine
  Fruit
  Human-reviewed profile
  Specific primary bioactive compounds and their precise mechanisms of action for Ocean Grapevine (*Coccoloba uvifera*) are not extensively do…
• Ocean Kelp
  Other
  Human-reviewed profile
  Ocean Kelp, rich in polysaccharides and fucoxanthin, supports thyroid health due to its iodine content and provides potent antioxidant prote…
• Ocean Palm Kernel Extract
  Extract
  Human-reviewed profile
  Ocean Palm Kernel Extract, derived from Elaeis guineensis, is rich in bioactive compounds like tocotrienols and fatty acids. These compounds…
• Ocimum gratissimum (African Basil / Scent Leaf)
  African
  Human-reviewed profile
  Ocimum gratissimum, or African Basil, contains eugenol, a potent phenolic compound that exhibits significant anti-inflammatory and antimicro…
• Ocimum sanctum
  Ayurveda
  Human-reviewed profile
  Holy basil (Ocimum sanctum) contains eugenol, rosmarinic acid, and ursolic acid that modulate cortisol levels and HPA axis function. Clinica…
• Ogeechee Berry
  Berry
  Human-reviewed profile
  Ogeechee berry (Nyssa ogeche) contains high concentrations of citric acid (5-7%) and ascorbic acid (50-100 mg/100g) that provide antioxidant…
• Ogeechee Lime
  Fruit
  Human-reviewed profile
  Ogeechee Lime (Nyssa ogeche) is recognized for its traditional uses and a general nutritional profile, including some polyphenol content. Ho…
• Ogeechee Tupelo
  Bark
  Human-reviewed profile
  Ogeechee tupelo (Nyssa ogeche) bark has no published peer-reviewed phytochemical or pharmacological studies as of mid-2025; however, genus-l…
• Ohelo Berry
  Fruit
  Human-reviewed profile
  Ohelo berries are rich in phenolics and proanthocyanidins, particularly A-type linkages, similar to those found in cranberries. These compou…
• Okinawan Olive
  Fruit
  Human-reviewed profile
  Okinawan Olive refers to olive leaf extract formulations marketed for longevity benefits, containing oleuropein (20-50 mg per dose) and hydr…
• Okinawan Purple Sweet Potato Leaf
  Leaf/Green
  Human-reviewed profile
  Okinawan Purple Sweet Potato Leaf is abundant in anthocyanins, phenolic acids, and flavonoids, which contribute to its potent antioxidant an…
• Okinawan Rainforest Nut
  Nut
  Human-reviewed profile
  The 'Okinawan Rainforest Nut' is not a recognized botanical species in any peer-reviewed scientific database, taxonomic registry (ITIS, GRIN…
• Okinawan Wild Almond
  Nut
  Human-reviewed profile
  Okinawan Wild Almond delivers oleic acid and vitamin E tocopherols that modulate endothelial nitric oxide synthase activity, supporting card…
• Okra Mucilage
  Other
  Human-reviewed profile
  Okra mucilage, rich in highly viscous polysaccharides and phenolic compounds such as quercetin derivatives, forms a soothing gel that aids d…
• Okra Pods
  Vegetable
  Human-reviewed profile
  Okra pods are rich in polyphenols and polysaccharides, which contribute to their antioxidant and antidiabetic effects. These compounds help …
• Olallieberry
  Berry
  Human-reviewed profile
  Olallieberry (Rubus ursinus × Rubus idaeus hybrid) contains 150-300 mg/100g of anthocyanins including delphinidin 3-O-galactoside and cyanid…
• Oleanolic Acid
  Compound
  Human-reviewed profile
  Oleanolic acid is a pentacyclic triterpene that modulates inflammatory pathways through NF-κB inhibition and enhances liver detoxification e…
• Oleic Acid (Omega-9)
  Other
  Human-reviewed profile
  Oleic acid is a monounsaturated omega-9 fatty acid that comprises 70-80% of olive oil's fatty acid content. It modulates cholesterol metabol…
• Oleoylethanolamide (OEA)
  Other
  Human-reviewed profile
  Oleoylethanolamide (OEA) is a naturally occurring fatty acid amide that regulates appetite and weight management by activating PPAR-alpha re…
• Olive Berry
  Fruit
  Human-reviewed profile
  Olive berry contains high concentrations of oleuropein and hydroxytyrosol, powerful phenolic compounds that provide cardiovascular and immun…
• Olive Oil
  Other
  Human-reviewed profile
  Olive oil is rich in oleic acid (55–83% of total fatty acids), hydroxytyrosol, oleocanthal, and oleuropein—phenolic compounds that confer ca…
• Ololiuqui Seed
  Seed
  Human-reviewed profile
  Ololiuqui seeds contain D-lysergic acid amide (ergine) and D-isolysergic acid amide as primary bioactive compounds. These ergoline alkaloids…
• Olopua Olive
  Other
  Human-reviewed profile
  Olopua Olive, primarily referencing products from Olea europaea, is rich in oleuropein, a key phenolic compound. This compound contributes t…
• Omani Frankincense
  Resin
  Human-reviewed profile
  Omani Frankincense, derived from Boswellia sacra, owes its therapeutic effects primarily to boswellic acids. These compounds exert anti-infl…
• Omani Wild Lime
  Fruit
  Human-reviewed profile
  Omani Wild Lime fruit contains potent flavonoids, limonoids, and D-limonene, which contribute to its therapeutic effects. These compounds ex…
• Omija (Schisandra chinensis, Korean)
  Traditional Chinese Medicine
  Human-reviewed profile
  Omija (Schisandra chinensis) contains lignans like schisandrin B that enhance liver glutathione levels and cytochrome P450 detoxification en…
• Omija Berry
  Berry
  Human-reviewed profile
  Omija berry (Schisandra chinensis) contains unique lignans like schisandrins and abundant polyphenols that provide potent antioxidant activi…
• Onion Seed
  Seed
  Human-reviewed profile
  Onion seed (Allium cepa L.) contains sulfur compounds like methiin and ethiin that produce persulfides regulating cell proliferation and apo…
• Oolong Tea Leaf
  Leaf/Green
  Human-reviewed profile
  Oolong tea leaf (Camellia sinensis) contains unique polyphenols including theasinensins and catechins that target multiple cellular pathways…
• Oplopanax Root
  Root/Rhizome
  Human-reviewed profile
  Oplopanax Root, from Oplopanax horridus, contains bioactive polyynes like falcarindiol, which exhibit potent antibacterial and antiprolifera…
• Opuntia Fruit
  Fruit
  Human-reviewed profile
  Opuntia ficus-indica fruit contains phenolic compounds including quercetin, kaempferol, and their glycosides that function as antioxidants b…
• Ora-pro-nobis Leaf
  Leaf/Green
  Human-reviewed profile
  Ora-pro-nobis Leaf is rich in diverse bioactive compounds, including phenolic compounds, flavonoids, and carotenoids. These compounds primar…
• Oral Hyaluronic Acid (Low Molecular Weight)
  Other
  Human-reviewed profile
  Low molecular weight hyaluronic acid is a smaller form of hyaluronic acid that penetrates tissues more effectively than high molecular weigh…
• Orange Blossom
  Flower
  Human-reviewed profile
  Orange Blossom, primarily derived from *Citrus aurantium*, is rich in bioactive compounds like flavonoids, polyphenols, and terpenes. These …
• Orange Blossom Vine Syrup
  Syrup
  Human-reviewed profile
  Orange blossom syrup contains antioxidant polyphenols like flavonoids and vitamin C, which neutralize free radicals to prevent cellular dama…
• Orangeberry
  Berry
  Human-reviewed profile
  Orangeberry contains high concentrations of flavonoids, phenolic acids, and carotenoids that activate the Nrf2 antioxidant pathway and inhib…
• Oregano Oil (Carvacrol)
  Other
  Human-reviewed profile
  Oregano oil contains 60-80% carvacrol, a phenolic compound that disrupts bacterial cell membranes and inhibits biofilm formation. It demonst…
• Oregano Oil (Origanum vulgare)
  Other
  Human-reviewed profile
  Oregano oil contains carvacrol and thymol, potent phenolic compounds that disrupt bacterial cell membranes and inhibit biofilm formation. Th…
• Oregon Grape (Mahonia aquifolium)
  Native American
  Human-reviewed profile
  Oregon grape (Mahonia aquifolium) contains berberine, an isoquinoline alkaloid that demonstrates antimicrobial activity against Candida, H. …
• Oregon Wood Sorrel
  Leaf/Green
  Human-reviewed profile
  Oregon Wood Sorrel contains oxalic acid, flavonoids, and other phenols which exert antioxidant, anti-inflammatory, and antimicrobial effects…
• Orengedokuto (Coptis Detoxifying)
  Traditional Chinese Medicine
  Human-reviewed profile
  Orengedokuto is a traditional Japanese Kampo formula containing four herbs that primarily enhances liver detoxification through berberine an…
• Orinoco Cacao Pod
  Other
  Human-reviewed profile
  Orinoco Cacao Pod is rich in bioactive phenolic compounds, including flavonoids like epicatechin and catechin, which primarily function as p…
• Osmotically Dehydrated Cranberry
  Fruit
  Human-reviewed profile
  Osmotically dehydrated cranberry contains concentrated proanthocyanidins (PACs) that prevent bacterial adhesion to urinary tract epithelial …
• Osmotically Dehydrated Mango
  Fruit
  Human-reviewed profile
  Osmotically dehydrated mango is a concentrated fruit product rich in beta-carotene, vitamin C, and dietary fiber that supports immune functi…
• Osmotically Dehydrated Pineapple
  Fruit
  Human-reviewed profile
  Osmotically dehydrated pineapple retains bioactive bromelain enzymes that support protein digestion and reduce inflammatory cytokines. This …
• Oubanguia Nut
  Nut
  Human-reviewed profile
  Information on the Oubanguia Nut is extremely limited in scientific literature, precluding the identification of specific key compounds or t…
• Oubli Berry
  Berry
  Human-reviewed profile
  Oubli Berry, derived from *Thaumatococcus daniellii*, owes its unique taste-modifying properties primarily to the protein miraculin. This co…
• Oxalis Leaf
  Leaf/Green
  Human-reviewed profile
  Oxalis leaf is rich in flavonoid C-glycosides—vitexin, isovitexin, and orientin—along with phenolic acids that exhibit potent DPPH/ABTS radi…
• Oxaloacetate
  Other
  Human-reviewed profile
  Oxaloacetate is a critical metabolic intermediate in the Krebs cycle and gluconeogenesis pathways. It directly supports cellular energy prod…
• Oxeye Daisy Kernel Powder
  Other
  Human-reviewed profile
  Oxeye Daisy (Leucanthemum vulgare) powder, particularly from flowers or the whole plant, contains bioactive compounds such as terpenes, flav…
• Oxidase Enzyme
  Enzyme
  Human-reviewed profile
  Oxidase enzymes are a class of oxidoreductases that catalyze oxidation-reduction reactions, utilizing molecular oxygen as the electron accep…
• Oxidoreductase
  Enzyme
  Human-reviewed profile
  Oxidoreductases are a vital class of enzymes that facilitate electron transfer between molecules, crucial for various metabolic pathways. Th…
• Oxidoreductase Enzyme
  Enzyme
  Human-reviewed profile
  Oxidoreductase enzymes are a critical class of enzymes that catalyze oxidation-reduction (redox) reactions by transferring electrons between…
• Oxiracetam
  Compound
  Human-reviewed profile
  Oxiracetam is a racetam nootropic supplement that enhances cognitive function by modulating AMPA glutamate receptors and increasing acetylch…
• Oxyresveratrol (Stilbene)
  Compound
  Human-reviewed profile
  Oxyresveratrol is a stilbene compound found in mulberry that demonstrates potent antioxidant activity through free radical scavenging mechan…
• Oxytocin (Intranasal)
  Other
  Human-reviewed profile
  Oxytocin intranasal is a neuropeptide hormone administered through nasal spray that directly targets oxytocin receptors in the brain. It enh…
• Oyster Mushroom (Pleurotus ostreatus)
  Mushroom/Fungi
  Human-reviewed profile
  Oyster Mushroom (Pleurotus ostreatus) enhances immune function through beta-glucans that activate macrophages and natural killer (NK) cells,…
• Oyster Plant
  Leaf/Green
  Human-reviewed profile
  Oyster Plant (Tradescantia spathacea) contains phenolic compounds and anthocyanins that modulate inflammatory mediators and enhance antioxid…
• Oysters
  Other
  Human-reviewed profile
  Oysters are prized saltwater bivalves rich in bioactive compounds like peptides and proteins, which exert significant antioxidant activity b…
• Ozonated Water
  Other
  Human-reviewed profile
  Ozonated water is created by infusing water with ozone (O₃) gas, forming a solution with potent oxidative and antimicrobial properties. Its …