A randomized trial run with Nestlé Research found that 714 mg of nicotinamide (vitamin B3) and 19 mg of pyridoxine (vitamin B6) a day for nine days increased muscle stem cell activity and the share of regenerating fibres after a session of damaging muscle contractions in young men. Soreness, strength and blood markers of muscle damage did not change. For a supplement brand, the result is interesting but early. The trial dose is above Canada's limit for niacinamide, B6 at that level needs a nerve warning on Canadian labels, Nestlé has filed patent applications on the combination, and no monograph allows a muscle repair claim for these vitamins.
This post covers what the research showed, what it didn't, and what a brand can do with it today in Canada and the US.
What did the Nestlé research find?
There are two studies.
The first, published in the Journal of Clinical Investigation in 2024, screened compounds in human muscle cells and tested them in mice. Nicotinamide and pyridoxine together increased the growth of muscle stem cells (satellite cells) and improved regeneration after injury, including in old mice. The authors trace the effect to specific signalling pathways in the stem cells (CK1/β-catenin and AKT), not to the vitamins' general role in energy metabolism.
The second is the human trial, published in Advanced Science in 2026 by the University of Copenhagen and Nestlé Research and funded by Nestlé. In it:
- 43 men aged 18 to 49 enrolled, and 39 completed the study.
- One leg was put through a single session of damaging eccentric contractions, induced with electrical muscle stimulation, and the men then took 714 mg of nicotinamide and 19 mg of pyridoxine a day, or a placebo, for nine days.
- Eight days after the session, muscle biopsies from the supplement group had 29% to 67% more active stem cells per damaged fibre and 37% more regenerating fibres than the placebo group.
- The supplement was well tolerated.
What the trial did not show matters as much. Soreness, strength and creatine kinase (a blood marker of muscle damage) changed in both groups without a difference from the supplement. The damage came from one controlled session in one leg, not from ordinary training, and only the combination was tested, not either vitamin alone. It is a single trial, run and paid for by the company developing the combination, and it has not been repeated independently.
What are the safety and regulatory limits?
The trial doses are far above everyday vitamin amounts:
- 714 mg of nicotinamide is about 45 times the US recommended intake of niacin for men and far above the 35 mg upper intake level the US sets for supplemental niacin.
- In Canada, Health Canada's multi-vitamin/mineral monograph caps niacin and niacinamide at 500 mg a day in total, below the trial dose.
- Health Canada's 2026 safety review found a possible link between vitamin B6 at 10 mg a day or more and peripheral neuropathy. The monograph now requires a caution at that level: stop use and ask a health care practitioner if you develop numbness, tingling or pain in the extremities. The trial's 19 mg is above that threshold.
Is the combination patented?
Nestlé has filed patent applications on it. One of them, EP 4236945, covers compositions containing nicotinamide and vitamin B6 for promoting muscle growth, and related applications cover recovery after muscle injury. Check the current status of these filings, and get freedom-to-operate advice, before you build a product around the combination or its research.
What claims could a B3 and B6 product make?
In Canada, B3 and B6 are licensed under the multi-vitamin/mineral monograph, which authorizes claims such as "helps in energy metabolism and tissue formation" and, for B6, "helps to form red blood cells". The monograph does not allow the nutrient claim to be spelled out as carbohydrates, fats or proteins. None of its claims mentions muscle repair or recovery. A muscle repair claim would need a non-compendial application supported by evidence, and at the trial dose the product would also be outside the monograph's niacinamide limit. Our NPN application service can tell you which route a formula falls into.
In the US, a dietary supplement can carry a structure/function claim with the FDA disclaimer and a notice to the FDA within 30 days of first marketing it, but the claim still has to be substantiated. Based on this trial, a claim about muscle stem cell activity after strenuous exercise is the most the evidence supports. Faster recovery, less soreness or more strength go beyond what the study measured.
What can a brand do with this research today?
Treat it as an early signal rather than a product brief.
- Use B vitamins in a sports formula at monograph doses, with the claims the monograph allows, rather than borrowing the trial's results.
- If you want to build on the trial itself, start with a patent check and a regulatory plan, and expect a longer licensing route in Canada.
- Watch for independent replication. A second trial without the developer's involvement, measuring recovery people can feel, would change what can be claimed.
A custom formulation review can show where B vitamins fit an existing sports product, and our label compliance work covers the cautions and claims in both markets.
What should formulators know about these vitamins?
- Nicotinamide is the form of B3 that does not cause the flushing nicotinic acid does.
- Pyridoxine hydrochloride is the usual form of B6 in supplements. B6 is sensitive to light, so protect it in processing and packaging.
- Both are water-soluble and fit capsules, tablets and powders. At the trial doses, the nicotinamide alone is a large amount to fit into a single capsule, so powders or two capsules are more practical.
FAQ
What did the Nestlé B3 and B6 study show?
In 39 young men, 714 mg of nicotinamide and 19 mg of pyridoxine a day for nine days after one session of damaging leg contractions increased muscle stem cell activity and regenerating fibres in biopsies. Soreness, strength and blood markers of muscle damage did not differ from placebo.
Can I sell a B3 and B6 muscle recovery supplement in Canada?
Not with a muscle recovery claim under the existing monographs. The multi-vitamin/mineral monograph allows claims such as energy metabolism and tissue formation, caps niacinamide at 500 mg a day and requires a nerve caution for B6 at 10 mg or more. A muscle claim needs a non-compendial application with evidence.
What dose of B6 needs a warning in Canada?
10 mg a day or more. The label must tell users to stop and ask a health care practitioner if they develop numbness, tingling or pain in the extremities.
Is the B3 and B6 combination patented?
Nestlé has filed patent applications on compositions containing nicotinamide and vitamin B6 for muscle growth and recovery. Check their status and get freedom-to-operate advice before launching a product based on the combination.
Can a US product claim it supports muscle repair?
A structure/function claim is possible with substantiation, the FDA disclaimer and a 30-day notice. The evidence comes from one company-funded trial that measured muscle stem cells, so keep the claim to what it showed and avoid recovery, soreness or strength claims.
If you are deciding whether B vitamins belong in a sports formula, tell us about the product and we will go through the doses, claims and regulatory route with you.
