Riboflavin 5 - Phosphate 60 Caps Thorne Research
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✅ Individuals with increased need for vitamin B2, whether due to diet, physical or mental exertion.
✅ Those looking to reduce feelings of fatigue or tiredness.
✅ Those seeking support for vision, especially under conditions of high visual strain.

Thorne Riboflavin 5-Phosphate – Active Vitamin B2 for Cellular Energy and Fatigue Reduction
Thorne Riboflavin 5-Phosphate is a vitamin B2 supplement in its active coenzymatic form (R5P), ready to be used by the body without additional liver conversion. It can be beneficial for those who want to support energy production, normal metabolism, the activation of other B vitamins, and cellular balance in daily life.
Vitamin B2 is essential for the body to produce energy, activate other B complex vitamins, and maintain proper cellular function. To be utilized by the body, common riboflavin must be converted into its active form — riboflavin-5'-phosphate (R5P). Individuals with compromised digestive systems, those taking certain medications, or those with genetic variants that hinder this conversion may not get the most out of this vitamin in its conventional form. Thorne's Riboflavin 5'-Phosphate provides 36.5 mg of riboflavin already in its active form per capsule, requiring no additional conversion by the body, in a gluten-free, soy-free, and dairy-free vegetable capsule.
✅ Contributes to energy-yielding metabolism and the reduction of tiredness and fatigue
✅ Supports the normal functioning of the nervous system and mucous membranes
✅ Participates in the protection of cells against oxidative stress
✅ Contributes to the maintenance of normal skin and vision
✅ Coenzymatic (active) form of B2 – high bioavailability
✅ Free from gluten, soy, and dairy – ideal for restrictive diets
The only active ingredient is vitamin B2 in the form of sodium riboflavin-5'-phosphate (R5P), providing 36.5 mg of riboflavin per capsule. R5P is the active coenzymatic form of vitamin B2 — the one the body uses directly, without needing additional conversion by the liver or digestive system. This makes it particularly relevant for people with compromised digestive function, irritable bowel syndrome, Crohn's disease, or those taking medication that interferes with riboflavin absorption. Vitamin B2 is also an essential cofactor for the activation of other B vitamins: it is necessary to activate vitamin B6, for the conversion of tryptophan to niacin (B3), and for the conversion of folate into its active forms. The product is not yeast-derived.
Excipients include hydroxypropyl methylcellulose capsule (vegetable cellulose), microcrystalline cellulose, silicon dioxide, and calcium laurate — all of vegetable or mineral origin. It contains no gluten, soy, dairy, artificial flavors, artificial colors, or unnecessary preservatives.
Informative note: Urine may appear bright yellow during riboflavin supplementation — this is a harmless and normal effect of this vitamin's metabolism, with no health implications.
Please note
- Bright yellow urine is a harmless and expected effect of riboflavin — it is not a cause for concern.
Vitamin B2 (as N Riboflavin 5 Phosphate), 36.5 mg / 2607%
Ingredients: Riboflavin-5-phosphate, hypromellose capsule (made from cellulose), microcrystalline cellulose (filler), silicon dioxide (separating agent), calcium laurate (superplasticizer).
1 Capsule per day
* NRV — Nutrient Reference Value.
** NRV not established.
💊 Food supplements are not a substitute for a varied and balanced diet or a healthy lifestyle.
🤰 If pregnant or breastfeeding, consult your doctor before taking this supplement.
⚠️ Not recommended in cases of hypersensitivity or allergy to any of the ingredients, or when interactions between another product and any of its constituents have been described.
🕐 Do not exceed the recommended daily dose. Keep out of reach and sight of children.
🌡️ Store in a cool, dry place, away from light.
FAQs
Thorne's Riboflavin 5'-Phosphate is a vitamin B2 supplement in its active form (R5P), which can contribute to energy production, normal metabolism, the activation of other B vitamins, the maintenance of red blood cells, and cell protection. It is particularly relevant for those who have difficulty converting conventional riboflavin.
It can be useful for those with persistent fatigue, compromised digestive function, genetic variants affecting B vitamin metabolism (such as MTHFR variants), or those taking medication that may interfere with riboflavin absorption. People with frequent migraines, anemia, skin or mucous membrane disorders, burnout syndrome, or high homocysteine levels may benefit from an adequate intake of active B2 — always in addition to medical follow-up.
Conventional riboflavin requires conversion by the digestive system to become active. R5P is already in the coenzyme form and is directly utilized by the body. For individuals with compromised digestive function or genetic variants that hinder this conversion, R5P may be the preferred option.