Manufacturers
- O Essentials
- O N E Natural Experience
- O Nutritions
- O Positiv, LLC
- O'My Products, Inc.
- O2 Worldwide
- Oat Mama
- Oats Overnight
- Obesity Research Institute
- OCCY Laboratoire
- Ocean Avenue
- Ocean Essence
- Ocean Horizon Enterprises Limited
- Ocean Nutrition Canada
- Ocean Spray
- Oceanblue LLC
- Oceanus Naturals
- OCuSOFT
- Ocvita Labs LLC
- Odan Laboratories Ltd
- Official HCG Diet Plan
- Ohana Health
- OIS (M) Sdn Bhd
- Okuma Nutritionals
- Ola Loa, LLC
- Olaax Corp
- Olay Vitamins
- Old East Main Co.
- Old Ocean House Farms
- Old School Labs
- Ole Henriksen
- Oleda and Company, Inc.
- Oleifici Mataluni
- Olipop, Inc.
- Olive Leaf Australia
- Olive Lifesciences Pvt. Ltd.
- Olivus
- Olly Nutrition
- OLLY Public Benefit Corp.
- Olympia Nutrition
- Olympian Labs
- Olympus Labs
- Olympus Labs UK
- Olympus Performance
- Om Mushroom Superfood
- OM Pharmaceuticals LTD
- OM-CHI Herbs
- Omax Health
- Omega 3 Chia
- Omega Alpha Pharmaceuticals
- Omega Biotech Corporation
- Omega Laboratories Limited
- Omega Natural Science Inc.
- Omega Nutrition
- Omega Pharma Ltd.
- Omega Sports
- Omega Supreme Nutrition
- OmegaK, Inc.
- Omica Organics
- OmneDiem
- Omni Nutraceuticals
- OmniActive Health Technologies
- Omnicron International
- Omnilife
- Omnilife Canada Inc.
- Omniq, LLC
- Omnitrition International, Inc.
- Omnivista Health Solutions
- Omojo Health USA
- ON Distribution LLC
- One Minute Miracle
- OneBode Inc
- Oneel Corporation Ltd
- OneSecond Supplements
- OnGo LLC
- Online Future Inc.
- Only Natural Products Ltd.
- Only Natural, Inc.
- Only Protein Corporate
- Onnit Labs
- Onnx Nutrition
- Oona Health Inc.
- OP2 Labs
- Openfit, LLC
- Opportuniteas Inc.
- Optalife Nutrition
- Opti-Choice
- Opti-Nutra Ltd
- Optimal Carnivore LLC
- Optimal Health Products
- Optimal Health Systems
- Optimal Labs Direct LLC
- Optimal Labs LLC
- Optimal Naturals
- Optimal Nutrition LLC
- Optimal Supplement Nutrition LLC
- Optimal Therapeutics
- Optimally Organic
- Optimox Corporation
- Optimum Health Care
- Optimum Health Nutrition
- Optimum Health Services
- Optimum Nutrition
- Option Biotech
- OptiPure Chemco Industries Inc.
- OptiYouRX
- Opus Pharma 2010
- Ora Organic
- Orafti Active Food Ingredients
- Oragenics, Inc.
- OraHealth
- Orajel
- Orange Naturals
- Orange Peel International
- Orbus Pharma Inc
- Orchid Wellness Inc
- Oregon's Wild Harvest
- Orenda International
- Orgain
- Orgain, Inc
- Orgain, LLC
- Organa International
- Organic African Red Tea Inc.
- Organic Aura International
- Organic Aura International Pvt Ltd
- Organic Aura Naturals
- Organic Defense
- Organic Evolution
- Organic Food Bar Inc
- Organic Hope
- Organic India Pvt. Ltd
- Organic India USA
- Organic Muscle, Inc.
- Organic Olivia LLC
- Organic Products LLC
- Organic Rosehip Pty Ltd
- Organics Ocean
- Organics Overseas Inc
- Organifi LLC
- Organifi LLC.
- Organika Health Products Inc.
- Organix-South Inc
- Organixx
- Organo Gold Enterprises Inc (USA)
- Organon
- Oriental Herb Company
- Origin Biochemical Laboratory, Inc.
- Origin BioMed Inc.
- Origin Labs, LLC
- Origin Nutraceutical
- Orjene
- Ormus Minerals
- Orovo, LLC
- Orphic Nutrition
- Ortho Dermatologics
- Ortho Molecular Products, Inc.
- Orzax Inc.
- Osack
- OSATO Distribution Ltd
- Osis Nutrition Inc
- Oslo Health Solutions
- Osmo Pharma
- OSMO Therapy
- OSN Labs
- Oso Yummy
- Osotspa Co., Ltd.
- OSTA/CARD
- Osteocalth Health Ltd
- Osteogenic Core Technologies (OCT)
- Osumex Natural Alternatives Ltd
- Osyris Nutrition Lab
- OTC Pharma International
- OTC Pharmaceutical Products
- Otigh International Group Inc.
- Our Health Co-op, Inc.
- Outbreak Nutrition
- Outlaw Aesthetics
- Outlaw Laboratory
- Outlier Nutrition
- Outwork Nutrition
- Ovation Lifestyles
- Overpowered Labs, LLC
- OVOS Natural Health
- Oweli, Inc.
- OX Nutrition
- OXIS Health Products, Inc.
- Oxyfit Xtreme
- Oxyfresh Worldwide, Inc.
- Oxylent
- OxyLife
- OxyTrust
- OXYwater
- OXZGEN, Inc.
- Oy Sinebrychoff Ab
