Canvuparatide
A parathyroid hormone fragment built to release itself slowly, so one injection a week can stand in for a hormone the body no longer makes
People with hypoparathyroidism make too little parathyroid hormone (PTH), so their blood calcium drifts low and most take calcium tablets and active vitamin D several times a day. Canvuparatide, developed by MBX Biosciences as MBX 2109, is the first 32 amino acids of human PTH with two fatty side chains attached and a short cap on one end that falls away by itself after injection. The cap makes it a prodrug and the fatty chains keep the active peptide in the blood for about a week. Published human data cover healthy volunteers only; the company reports that its phase 2 trial in patients met its main goal, and a phase 3 trial started in 2026. It is not approved anywhere.
Used in human trials: 200, 400, 600 or 900 µg, Once a week, Subcutaneous (Phase 1: repeated doses, healthy adults) Details ↓
Recommended Dosing
Used in human trials
Typical range200–900 µg · once a week Human studyPMID 39574220compare across peptides →
No manufacturer dose exists for this use: these are amounts given in published trials, not recommendations.
Work out syringe units → · New to syringes? · All dosing data ↓ · Dose and vial tracker · Is this vial OK?
What is it?
Four small parathyroid glands in the neck set the level of calcium in the blood. When calcium dips they release parathyroid hormone, which pulls calcium out of bone, tells the kidneys to hold on to calcium and let phosphate go, and switches on the active form of vitamin D so the gut absorbs more. Lose the glands, most often as a side effect of thyroid or neck surgery, and that whole loop stops. The usual fix is calcium tablets and calcitriol, taken in divided doses through the day. They raise blood calcium, but without the hormone the kidneys keep passing calcium into the urine, and over years that can lead to kidney stones and calcium deposits in the kidney. The 2026 reviews carded below describe the move towards replacing the hormone instead.
Replacing it well means keeping the receptor switched on steadily rather than in bursts, and that is what the newer long-acting analogues are reviewed as trying to do. Developers have taken different routes. Palopegteriparatide, already approved, hangs PTH(1-34) on a carrier that lets it go slowly through the day. Eneboparatide is a different receptor agonist whose calcium effect outlasts the drug. Canvuparatide is a third approach, aimed at one injection a week.
Its design has two parts, both visible in its registered structure. The first is the peptide itself: residues 1 to 32 of human PTH, the stretch that switches on the type 1 PTH receptor, followed by an extra lysine. That lysine carries a long fatty-acid chain on a short linker, which its developers added to slow the peptide's removal from the blood. The second is a two-residue cap on the front end, a D-lysine and an N-methylglycine, with a second fatty chain on that D-lysine. With the cap on, the molecule is a prodrug. Its developers report that the cap removes itself by folding back and cyclising at a rate set by body temperature and pH, leaving the active peptide behind.
The point of that arrangement is a flat profile. In the published phase 1 trial in healthy adults, the prodrug had a half-life of 79 to 95 hours and the active peptide 184 to 213 hours, which is close to nine days at the top of the range, and exposure rose steadily with dose. Four weekly injections at up to 900 micrograms caused no serious or severe adverse events; reactions where the needle went in were the commonest drug-related complaint. The discovery paper adds the earlier steps: in cells carrying the human receptor the released peptide acted much like PTH(1-34), and in rats whose parathyroid glands had been removed it brought calcium back to normal.
What the published record does not yet contain is a trial in patients. The phase 2 Avail study gave canvuparatide or placebo to 64 adults with chronic hypoparathyroidism for 12 weeks, and MBX Biosciences reported in September 2025 that 63% of treated patients met a composite goal (normal blood calcium without active vitamin D or therapeutic calcium) against 31% on placebo. That is the company's own summary of an unpublished trial; the placebo rate is high, the groups were small (48 against 16), and no journal paper had appeared on PubMed by November 4, 2026. A phase 3 trial of about 160 patients (NCT07699471) opened in August 2026 with a 26-week primary end point.
Canvuparatide is an investigational drug and is not available outside those trials. Any PTH replacement in hypoparathyroidism has to be set against frequent blood calcium checks: too much drives calcium too high, and stopping calcium and vitamin D too quickly can let it crash. A weekly drug that stays in the body for days also takes days to wash out if the dose turns out to be too high; in phase 2, according to the company, doses were changed only every two weeks and in 200-microgram steps.
Mechanism of Action
Canvuparatide is a slow-release form of a PTH fragment. Once the cap at its front end has come off, the peptide that remains switches on the same receptor as the hormone the patient lacks, and a fatty side chain keeps it in circulation for days.
Type 1 PTH receptor in bone and kidney
The released peptide is PTH residues 1 to 32 plus an acylated lysine. In cells carrying the human type 1 PTH receptor it raised cyclic AMP to the same degree as PTH(1-34) (PMID 41780637); that receptor is how PTH frees calcium from bone and keeps it in the kidney.
A cap that removes itself
A two-residue extension on the N-terminus (D-lysine and N-methylglycine, FDA GSRS UNII 7YT49ZX2QZ) keeps the molecule in its prodrug form. The developers report that it comes off through an internal cyclisation whose speed is governed by temperature and pH, so the active peptide appears gradually (PMID 41780637).
Fatty chains slow clearance
Each of the two lysines carries an 18-carbon diacid chain on a short linker (GSRS). In healthy adults that gave the active peptide a half-life of 184 to 213 hours after weekly dosing, long enough for one injection a week (PMID 39574220).
Calcium up, bone formation on
In rats without parathyroid glands it brought blood calcium back into the normal range and raised bone formation in step with dose (PMID 41780637). This is animal work; the matching human data are the company's phase 2 summary, not a published paper.
Published Research
These are the studies of canvuparatide read from their PubMed abstracts on November 4, 2026. The published record is small: one phase 1 trial in healthy adults reported on its own, one discovery paper that combines laboratory and animal work with the single-dose part of that trial, and two broad reviews from 2026. The reviews' titles do not name the drug; they are carded because their abstracts name it among the new long-acting PTH treatments. The phase 2 results in patients are known only from the company's release and are described in the overview, not carded.
Phase 1: four weekly doses in healthy adults
Forty healthy adults (average age 43, about a fifth women) were randomised four to one to canvuparatide or placebo, injected under the skin once a week for four weeks at 200, 400, 600 or 900 micrograms, eight people per dose. Adverse events of any kind were reported by half to seven in eight people on the drug and a quarter on placebo, none of them severe or serious, and injection-site reactions were the commonest drug-related event. The prodrug's half-life was 79 to 95 hours and the active peptide's 184 to 213 hours, with exposure rising with dose and over time and a flat level across the week. The authors judged that profile suitable for weekly dosing and picked doses for later trials. Registered as NCT05158335; MBX Biosciences staff are among the authors.
Discovery paper: cells, rats, monkeys and single doses in people
Mostly laboratory and animal work. In human cells engineered to carry the type 1 PTH receptor, the active peptide released from the prodrug raised cyclic AMP about as strongly and as selectively as synthetic PTH(1-34). In healthy rats dosed daily for 28 days and in cynomolgus monkeys given single doses, blood levels of prodrug and active peptide rose in proportion to dose and tracked rises in blood calcium. In rats whose parathyroid glands had been removed, it returned calcium to normal and increased bone formation with dose. In the single-dose part of the phase 1 trial, 50 to 600 micrograms under the skin were well tolerated in healthy volunteers, with mean half-lives of 81 to 101 hours for the prodrug and 133 to 186 hours for the active peptide.
From laboratory to clinic
A broad review of diagnosis and treatment in chronic hypoparathyroidism, written by an international group that includes an author of both canvuparatide papers. It groups canvuparatide with palopegteriparatide and eneboparatide as PTH analogues whose extended action keeps the receptor switched on and cuts the need for active vitamin D and calcium, and sets them beside calcilytics, parathyroid transplantation and stem-cell work.
Clinical trials and recent approvals
A review of the causes, complications and treatment of hypoparathyroidism. It explains why calcium and active vitamin D fall short of real hormone replacement, presents palopegteriparatide as the established long-acting option, and lists MBX 2109 with eneboparatide and the calcilytics among the investigational therapies still under study.
Dosing Data
Canvuparatide has no approved label. Both rows below come from the published phase 1 trial in healthy adults, from its two abstracts, so they record what volunteers were given to measure safety and blood levels, not a treatment dose. The patient trial used different amounts. According to MBX Biosciences' release of September 22, 2025, the phase 2 Avail trial (NCT06465108) started patients on 400, 600 or 800 micrograms a week for four weeks and then allowed changes in 200-microgram steps every two weeks for eight more; the extension study's registry record (NCT06531941) allows weekly doses between 200 and 1,600 micrograms. Those amounts are not tabled because no trial paper or posted results record reports them yet.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
What a Buyer Needs to Know
What is sold, how it is mixed, stored and taken, and what is known about its safety, quality and legal status. Each part names its source. Where we have none, it says unknown.
What is sold
Unknown: we hold no label and no published test that says what forms or vial sizes Canvuparatide is sold in. A vial's own label is a seller's claim, not a source.
Mixing a vial: a worked example
An arithmetic example, not a recommendation: a 5 mg vial mixed with 2 mL of bacteriostatic water holds 2,500 mcg per mL, so every 10 units on a U-100 insulin syringe hold 250 mcg. 200 µg, the first amount in the “Phase 1: repeated doses, healthy adults” row (200, 400, 600 or 900 µg) is 8.0 units (0.080 mL). If your vial or water differ, the numbers change: use the reconstitution calculator.
Source: dose: Used in human trials, PMID 39574220 (Dosing Data below); vial and water: the calculator's default example, not a vial size we have a source for.
Storage before and after mixing
Unknown: no label or published stability study on file says how to store Canvuparatide, before or after mixing. The mixing guide sets out the general rules, with their sources: keep a mixed vial in the fridge, and use it promptly, as the bacteriostatic water label says of any drug dissolved in it. The 28 days often quoted is the limit for an opened multiple-dose vial from a manufacturer, an outer limit set for sterility, not a time a mixed solution has been shown to keep. Nobody has published how long Canvuparatide stays intact once mixed.
How it is taken
As it was given in human studies: Subcutaneous (Once a week; Phase 1: repeated doses, healthy adults).
For injection technique, sites and needle disposal, see the mixing guide.
Source: Used in human trials: the route and frequency of each row in Dosing Data below.
What to expect, and when
How long it stays in the body: a half-life of 79-95 h (prodrug) and 184-213 h (active peptide) after four weekly doses. After about five half-lives almost none is left.
How long the doses were given: Phase 1: repeated doses, healthy adults: 4 doses (days 1, 8, 15 and 22); Phase 1: single doses, healthy adults: Single injection.
When effects appear: unknown; no source on this page gives a time to effect for Canvuparatide. Results reported in the studies are under Published Research.
Source: half-life: PMID 39574220; Used in human trials, the duration of each row in Dosing Data below.
Side effects, and when to stop or get help
From the Side Effects section: Injection-site reactions, the most common drug-related event in the repeated-dose phase 1 (PMID 39574220); No severe or serious adverse events at any dose up to 900 µg weekly in healthy adults (PMID 39574220); Single doses of 50 to 600 µg well tolerated in healthy volunteers (PMID 41780637); In phase 2, injection-site reactions in 19% on canvuparatide against 13% on placebo, with no related serious adverse events and no stops because of the drug (MBX Biosciences, September 22, 2025); The release gives no figures for high blood calcium, the main risk of any PTH replacement, so that question waits for the full paper. Full list and cautions ↓
When to stop or get help: unknown; no label or trial on file sets rules for stopping Canvuparatide. Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“From the published phase 1 work in healthy adults and the company's phase 2 release”).
Interactions
Unknown: a PubMed search for human interaction studies of Canvuparatide (reviewed 2026-11-04) found none. Unknown is not the same as safe to combine.
Every peptide's record, with its source: the interaction matrix.
Checking what you bought
Unknown: no published independent test of Canvuparatide products is in our lab-results database yet, so how products sold under this name measure up is not known.
To read a certificate of analysis, paste it into the COA decoder. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: In Clinical Trials (Not approved anywhere: Drugs@FDA and the openFDA label endpoint hold no record (searched November 4, 2026)). Sport: Prohibited (S0 catch-all).
Country by country ↓ · Regulatory tracker
Source: this entry's approval status and the WADA Prohibited List, as in Legal Status below.
Side Effects & Contraindications
Reported Side Effects
From the published phase 1 work in healthy adults and the company's phase 2 release. No patient trial has been published in a journal yet.
Contraindications & Cautions
There is no label. These cautions come from the trial designs and from the condition itself.
Legal Status
Canvuparatide is an investigational drug in phase 3 and has no approval in any country.
Frequently Asked Questions
?What is canvuparatide?
An investigational once-weekly injection for hypoparathyroidism, coded MBX 2109. It is the first 32 amino acids of human parathyroid hormone with fatty side chains attached and a cap that comes off by itself after injection, so the active hormone fragment is released slowly.
?Does it work?
The only patient data are the company's: in the 12-week phase 2 Avail trial, MBX Biosciences reported that 63% of 48 treated patients met its goal of normal calcium without active vitamin D or therapeutic calcium, against 31% of 16 on placebo. That has not yet been published in a journal, and phase 3 is under way.
?Why weekly when other PTH drugs are daily?
In healthy adults its active peptide had a half-life of 184 to 213 hours, about a week, because a fatty chain keeps it in the blood and the prodrug cap releases it gradually (PMID 39574220). The approved palopegteriparatide and the investigational eneboparatide are both injected daily.
?Is it the same as teriparatide or palopegteriparatide?
No. Teriparatide is PTH(1-34) with no modification, and palopegteriparatide is PTH(1-34) attached to a PEG carrier. Canvuparatide is a shorter fragment, PTH(1-32), with an added lysine, two fatty chains and a self-removing cap, which makes it a different molecule.
?Is it approved?
No. There is no FDA application or label as of November 4, 2026, and no approval elsewhere. A phase 3 trial opened in August 2026.
?Who makes it?
MBX Biosciences, based in Carmel, Indiana, which sponsors every registered trial of the drug (ClinicalTrials.gov). Both published papers include chemists at Indiana University among their authors (PMIDs 39574220, 41780637).
References
- [clinical-trial] Carney P, et al. "MBX 2109, A Once-Weekly Parathyroid Hormone Replacement Therapy Prodrug: Phase 1, First-In-Human, Randomized Trial." J Clin Endocrinol Metab, 2025;110(4):940-950. PMID: 39574220.
- [clinical-trial] Zhang F, et al. "Discovery and characterization of canvuparatide, a once-weekly parathyroid hormone analog for the treatment of hypoparathyroidism." Mol Metab, 2026;107:102345. PMID: 41780637.
- [review] Brandi ML, et al. "Hypoparathyroidism: translating science from the laboratory to the clinic." Lancet Diabetes Endocrinol, 2026;14(11):927-951. PMID: 42705258.
- [review] De Leo S, et al. "Hypoparathyroidism: a review of clinical trials and recent approvals." Expert Opin Pharmacother, 2026. PMID: 42907422.
- [pubmed] Tabacco G. "Exploring the Potential of Weekly Parathyroid Hormone Therapy for Hypoparathyroidism." J Clin Endocrinol Metab, 2025;110(11):e3899-e3900. PMID: 39834210.
- [manufacturer] MBX Biosciences press release, September 22, 2025: in the phase 2 Avail trial (NCT06465108) of once-weekly canvuparatide in 64 adults with chronic hypoparathyroidism, 63% (30/48) on canvuparatide met the week-12 responder end point against 31% (5/16) on placebo (p=0.042); 79% (44/56 evaluable) were responders at six months of the open-label extension; injection-site reactions in 19% against 13%; no related serious adverse events or discontinuations. https://investors.mbxbio.com/news-releases/news-release-details/mbx-biosciences-announces-once-weekly-canvuparatide-achieved
- [registry] ClinicalTrials.gov API v2, read November 4, 2026: MBX Biosciences sponsors five records. NCT05158335 (phase 1 in healthy adults, single ascending doses of 50 to 600 ug and repeated ascending doses, 76 enrolled, completed June 2023); NCT06496217 (phase 1, single doses in people with normal and impaired kidney function, 25 enrolled, completed September 2025); NCT06465108 (Avail, randomised, placebo-controlled phase 2 in hypoparathyroidism, 64 enrolled, primary completion May 2025); NCT06531941 (Avail-Ext, open-label extension, 60 enrolled, active, not recruiting; vials of 1.5 mg reconstituted to 1.0 mg/mL, weekly doses allowed from 200 to 1,600 ug); NCT07699471 (phase 3, randomised and placebo-controlled with an open-label extension, 160 planned, recruiting since August 26, 2026, primary completion estimated January 2028). None has results posted. https://clinicaltrials.gov/study/NCT06465108
- [other] FDA Global Substance Registration System, Canvuparatide, UNII 7YT49ZX2QZ (protein; INN 13262, USAN NO-166, CAS 2925554-87-4, NCI Thesaurus C211746; codes MBX 2109 and PPL 2717), read November 4, 2026: human parathyroid hormone fragment 1-32 (SVSEIQLMHNLGKHLNSMERVEWLRKKLQDVH) extended by a lysine after residue 32 and carrying a D-lysyl-N-methylglycyl extension at its N-terminus, both lysines bearing a 17-carboxyheptadecanoyl chain on gamma-glutamyl and aminoethoxy-ethoxy-acetyl linkers. https://gsrs.ncats.nih.gov/ginas/app/beta/substances/7YT49ZX2QZ
- [other] ChEMBL molecule CHEMBL6068219 (CANVUPARATIDE), read November 4, 2026: molecule type Protein, synonyms Canvuparatide (INN), Canvuparatida; highest clinical phase recorded 2. https://www.ebi.ac.uk/chembl/compound_report_card/CHEMBL6068219/
- [other] US FDA, Drugs@FDA and the drug label endpoint (openFDA), searched November 4, 2026: no application and no label record for canvuparatide.
Sources & Citations
The four studies carded above and the References-only editorial were read from their PubMed records on November 4, 2026. Structure, codes and registry numbers come from the FDA Global Substance Registration System (UNII 7YT49ZX2QZ) and ChEMBL (CHEMBL6068219); trial designs and status from ClinicalTrials.gov; the phase 2 result from MBX Biosciences' release of September 22, 2025, which will be replaced by the journal paper when it appears; United States status from Drugs@FDA and openFDA, all read the same day. Grey Peptides sells nothing and links to no vendor.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.