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Vitamins & vitamin-like compounds

Riboflavin 5′-Phosphate

Riboflavin 5′-Phosphate (phosphorylated riboflavin vitamer / FMN)

Riboflavin 5′-phosphate is flavin mononucleotide (FMN), a phosphorylated riboflavin vitamer often sold as a sodium salt; for a useful product comparison, compare the actual FMN salt and stated riboflavin equivalence instead of assuming “coenzymated” means clinically superior.

Water SolubleClinical ResearchForm Dependent EvidenceLow Risk Profile
Updated August 2026/4 min read/1 citations
Reviewed by the NootropicsIndex editorial team.Method: prioritize cited human research and official safety or regulatory sources; compare retailer-listed prices without endorsing products.Affiliate disclosure
01

What is it?

Identity and form

1

Riboflavin 5′-phosphate is flavin mononucleotide (FMN), a phosphorylated riboflavin vitamer often sold as a sodium salt.

02

Names, aliases and forms

AbbreviationsFMN; R5P
Spelling VariantRiboflavin-5-phosphate
03

Mechanisms of action

Biological role

1

FMN is a coenzyme precursor, although ingested phosphorylated riboflavin is processed during absorption.

04

Potential effects and evidence map

Evidence is strong for the essential nutrient role of riboflavin, but supplementation beyond adequacy has not been shown to produce a reliable general nootropic effect in well-nourished adults. Form-specific clinical uses should be evaluated separately.

Effect domainMagnitudeGrade
Mental energy / wakefulness1
UnknownConfidence: Medium

Evidence does not establish a reliable mental-energy effect from extra Riboflavin 5′-Phosphate in well-nourished healthy adults.

Note Essential nutrient biology and correction of inadequate status are different from enhancement.

1/5
C
Memory / learning1
UnknownConfidence: Medium

Direct evidence does not establish a general memory or learning benefit from Riboflavin 5′-Phosphate for healthy adults.

Note Keep form- and population-specific clinical research separate.

0/5
C
05

Typical dosages and timing

Nutrition benchmark11.1-1.3 mg/day

Use this to interpret labels and total intake, not as a demonstrated nootropic dose or recommended cycle.

06

Timing & effect horizon

Effect horizonUnknown
Unknown
What timing evidence can show1

No reliable acute nootropic onset, duration, The time for blood levels to fall by half during the final elimination phase.Source claim, or routine cycle is established for Riboflavin 5′-Phosphate. Nutrient-status correction and clinical follow-up periods answer different questions.

07

Safety, side effects and risk profile

Evidence uncertainty1
Confidence: High

Marketing claims extend beyond the established nutrient or precursor evidence.

Note Separate adequacy, biochemical activity, and enhancement outcomes.

1/5
B
Interaction risk1
Confidence: Medium

Medication, laboratory, and total-intake context can change the practical risk.

Note Check the official source for ingredient-specific interaction details.

1/5
B
GI discomfort1
Confidence: Medium

Tolerability varies with the specific form and amount consumed.

Note This row summarizes ordinary tolerability rather than special-population hazards.

1/5
B
Dose- and form-specific safety1

No tolerable upper intake level has been established; form-specific superiority claims are not supported by robust comparative human evidence.

08

Interactions and cautions

Medication and test context1

No clinically relevant medication interactions are known.

09

Practical buying and quality notes

  • Compare the actual FMN salt and stated riboflavin equivalence instead of assuming “coenzymated” means clinically superior.1
10

FAQ

What distinguishes Riboflavin 5′-Phosphate from related forms?

1

R5P, FMN, and riboflavin-5-phosphate are label variants; the counter-ion and riboflavin-equivalent amount should be clear.

11

References

  1. NIH Office of Dietary Supplements. Riboflavin Fact Sheet for Health Professionals.
Note

This page is informational and summarizes available evidence. It is not medical advice, a recommendation, or a substitute for guidance from a qualified clinician.