MOTS-c vs CB4211 isn't a choice between two names for the same thing. MOTS-c is a peptide, a short chain of protein building blocks, that the body makes. CB4211 is a modified relative developed as a drug candidate. Its human trial cannot establish a MOTS-c dose, side-effect rate, or expected benefit.
The distinction matters most when a CB4211 study dose appears online as instructions for MOTS-c. A number can come from a real trial and still belong to the wrong molecule.
MOTS-c vs CB4211: what each name means
Native MOTS-c means the original peptide sequence, containing 16 amino acids, the building blocks in that chain. Endogenous MOTS-c means the peptide made inside the body. A manufactured preparation is supplied from outside it.
The peptide's instructions sit in mitochondrial DNA, the genetic material inside cells' energy-making structures. Lee and colleagues' 2015 Cell Metabolism paper described it and studied treatment effects in cells and mice. Finding the peptide in human blood didn't establish what administering it would do.
CB4211 is an analog, meaning a deliberately modified relative of another molecule. CohBar, its developer, describes it as an analog of MOTS-c in its clinical results announcement below. The relationship explains why the two names appear together. It doesn't make CB4211 the original peptide under a different label.
| Question | MOTS-c | CB4211 |
|---|---|---|
| What does the name identify? | The original 16-amino-acid peptide | A modified drug candidate based on MOTS-c |
| Does the body make it? | Endogenous MOTS-c occurs naturally | CB4211 was developed as a medicine candidate |
| Can their doses be exchanged? | No validated conversion exists | Its study dose belongs to its own trial |
What the human CB4211 trial tested
CohBar's Phase 1a/1b study, NCT03998514, enrolled 88 people overall. Phase 1 means early human testing, focused mainly on safety and how the body handles a drug.
Healthy adults received single doses or repeated daily treatment for seven days. A separate group with fatty liver disease received daily treatment for 28 days. Treatment was subcutaneous, meaning under the skin.
Participants were assigned by chance to CB4211 or placebo, an inactive comparison. The study tracked unwanted health events, laboratory tests, heart recordings, and reactions where injections were given. It also planned measurements of drug levels over time. Weight, liver fat, and blood-sugar markers were exploratory measures: early signals to investigate further.
The registry lists completion on April 19, 2021, with its last posted update on May 11, 2021. It has no posted results. That describes the registry's results section; it doesn't mean the company never released findings.
What CohBar reported outside the registry
CohBar's August 10, 2021 announcement described a 25 mg daily CB4211 dose for four weeks. That is a historical trial fact, not a MOTS-c schedule.
Its accompanying presentation clarifies the participant counts. The fatty-liver portion enrolled 23 people; 20 completed the final assessments, including 11 receiving CB4211 and nine receiving placebo. The other three left before those assessments.
The company reported no serious adverse events across both study parts; its presentation lists injection-site reactions in 79% of people given CB4211 versus 33% given placebo. It also reported changes in liver blood tests and glucose, a weight trend, and liver-fat reductions in both groups. These were preliminary findings from a small, short study. A company announcement isn't a full clinical study report.
For someone considering MOTS-c, the limit comes before any result: those participants received CB4211. Their findings cannot supply a side-effect rate or a weight-loss forecast for native MOTS-c.
Why a CB4211 dose cannot become a MOTS-c dose
Milligrams describe an amount of material. They don't tell us how much intact peptide reaches the blood or how long it stays there. Changing a molecule or its preparation can change those things.
The CB4211 trial did not compare equal doses of CB4211 and native MOTS-c. It did not test switching between them. It therefore cannot establish a conversion, a starting amount, or a treatment duration for MOTS-c.
Even the injection preparation mattered within CB4211's own program. CohBar's presentation describes a pause after persistent material remained at injection sites, followed by a formulation change. Formulation means the complete preparation containing the drug. Evidence belongs to that preparation as well as the molecule.
The separate MOTS-c dosage guide covers how prescribing decisions are made without an established human dosing standard. The actual dose comes from the prescriber, rather than arithmetic using the analog's trial.
What about human studies of native MOTS-c?
Human measurements and human treatment answer different questions. In Reynolds and colleagues' 2021 Nature Communications study, ten young men exercised while researchers measured their body's MOTS-c. The men weren't given the peptide. Treatment experiments were in mice. The broader MOTS-c evidence guide separates those findings.
A separate registry entry, NCT07505745, describes planned native-MOTS-c treatment in 120 adults for 12 weeks. It lists recruiting status, with an April 1, 2026 update, but no results or numerical dose. Its participants are listed as having prediabetes, blood sugar above normal but below the diabetes range, and overweight or obesity.
That entry supplies a study plan, not completed treatment evidence. It cannot validate a dose borrowed from CB4211.
Where MOTS-c's regulatory status stands
Compounding means preparing medication for an individual prescription.
As of November 5, 2026, the day this article was written, an October 30 notice from the Department of Health and Human Services (HHS) announces a nonbinding draft compounding policy for six peptides, including MOTS-c. The policy states HHS does not intend to take enforcement action against state-licensed pharmacies, federal facilities, or licensed physicians when all ten conditions are met; the policy guide explains why this is neither drug approval nor a final ingredient-list rule.
The U.S. Food and Drug Administration (FDA) records no FDA-approved MOTS-c drug product in its May 11, 2026 review. Compounded MOTS-c prescribed through Promise is not FDA-approved. A licensed provider may still prescribe — that decision is between you and your doctor.
What this means for a MOTS-c visit
An IND, short for Investigational New Drug application, is a filing supporting a defined human investigation. FDA explains that it covers the study product, manufacturing information, and research plan. Permission to investigate isn't permission to market; the IND guide explains that distinction.
A useful prescribing conversation identifies the exact molecule, the goal, the evidence matching that goal, and a follow-up plan. At Promise, a licensed provider reviews every request, and not everyone qualifies. If MOTS-c is prescribed, a licensed U.S. compounding pharmacy prepares and dispenses the medication.
The prescription doesn't make it CB4211 or transfer that trial's findings. The provider sets the actual dose and monitoring for the individual preparation and patient.
