What Is Palopegteriparatide (Yorvipath)? The Once Daily PTH Replacement for Hypoparathyroidism and What the PaTHway Trial Found

Palopegteriparatide, sold as Yorvipath, is a once daily injectable form of parathyroid hormone (PTH) for adults with hypoparathyroidism, a condition in which the parathyroid glands do not make enough of the hormone that keeps your blood calcium steady. The FDA label describes it as "a parathyroid hormone analog (PTH(1-34)) indicated for the treatment of hypoparathyroidism in adults," and lists an initial U.S. approval in 2024.

If you follow peptide research, the interesting part of palopegteriparatide is not the hormone itself, because PTH fragments have been prescription drugs for decades. What stands out is the delivery. Palopegteriparatide is a prodrug, which means the PTH peptide is temporarily attached to an inert carrier and released slowly, so one injection a day produces steady hormone levels instead of a short spike. This article walks you through why that matters for hypoparathyroidism, what the PaTH Forward and PaTHway trials found, how dosing works on the label and which safety warnings come with it. It is educational content about published research rather than medical advice, and palopegteriparatide is a prescription drug used under close specialist supervision.

Hypoparathyroidism is a shortage of parathyroid hormone, and the standard treatment of calcium plus active vitamin D corrects your blood calcium without replacing the hormone. That distinction is the whole reason palopegteriparatide exists.

PTH normally handles several jobs at once. It pulls calcium from bone, tells your kidneys to hold on to calcium and release phosphate, and switches on the kidney enzyme that makes active vitamin D, which in turn raises how much calcium your gut absorbs. When PTH is missing, blood calcium drops and phosphate rises, and people can experience tingling, muscle cramps, fatigue and brain fog as a result.

Conventional therapy patches the calcium number by supplying large amounts of calcium and calcitriol, the active form of vitamin D. The PaTHway investigators described the limitation plainly, writing that conventional therapy "aims to alleviate hypocalcemia but fails to restore normal parathyroid hormone (PTH) physiology." Without PTH acting on the kidney, much of that extra calcium spills into the urine. High urine calcium is linked to kidney stones and kidney damage over time, which is why the trials tracked 24 hour urine calcium and kidney function so closely.

Palopegteriparatide works by releasing PTH(1-34), the active front portion of the parathyroid hormone molecule, slowly and steadily from an inactive carrier across the whole day. That fragment is the same active sequence used in teriparatide, the osteoporosis drug covered in our [teriparatide and abaloparatide guide](https://www.peptidepeppers.com/articles/teriparatide-abaloparatide-bone-building-peptides), and the real difference between the two drugs is the exposure pattern.

Teriparatide for osteoporosis delivers a short daily pulse, and a brief spike of PTH signal favors bone building. Hypoparathyroidism needs the opposite, which is a steady signal around the clock that resembles how a healthy parathyroid gland behaves. Palopegteriparatide was built for that job using Ascendis Pharma's TransCon technology, which is why researchers called it TransCon PTH during development.

The first in human study in healthy adults (Karpf and colleagues, Journal of Bone and Mineral Research, 2020, [doi.org/10.1002/jbmr.4016](https://doi.org/10.1002/jbmr.4016)) described TransCon PTH as an essentially inactive prodrug, transiently bound to an inert carrier and designed for sustained release of PTH(1-34). In that study free PTH showed an effective half life of approximately 60 hours, and its levels at steady state behaved much like a continuous infusion within the physiologic range for active PTH. The FDA label gives the same figure, stating that the apparent half life of PTH released from palopegteriparatide is approximately 60 hours. Our explainer on [peptide half life and dosing frequency](https://www.peptidepeppers.com/articles/peptide-half-life-dosing-frequency) walks you through why a long half life smooths out the peaks and troughs of once daily dosing.

PaTH Forward showed that most adults with hypoparathyroidism could stop active vitamin D and cut back their calcium supplements once they were on palopegteriparatide. The trial (Khan and colleagues, Journal of Clinical Endocrinology and Metabolism, 2022, [doi.org/10.1210/clinem/dgab577](https://doi.org/10.1210/clinem/dgab577)) enrolled 59 people, who were randomized to 15, 18 or 21 mcg a day or placebo for 4 weeks, followed by a 22 week extension in which the dose was titrated anywhere from 6 to 60 mcg a day.

By week 26, 91% of participants on palopegteriparatide had reached independence from standard care, which that trial defined as no active vitamin D and calcium of 500 mg a day or less. Mean 24 hour urine calcium dropped from 415 mg/24h at baseline to 178 mg/24h by week 26 while serum calcium stayed normal, and average scores on the SF-36 quality of life survey rose from below normal into the normal range.

PaTH Forward has also produced the longest follow up so far. A 3 year analysis (Rubin and colleagues, Journal of Bone and Mineral Research, 2026, [doi.org/10.1093/jbmr/zjag013](https://doi.org/10.1093/jbmr/zjag013)) reported that at week 162, "mean serum and median urine calcium remained within normal ranges and 91% of participants were independent from conventional therapy."

PaTHway, the main phase 3 trial, found that palopegteriparatide kept blood calcium normal while letting almost everyone stop conventional therapy, an outcome that placebo almost never reached. The trial (Khan and colleagues, Journal of Bone and Mineral Research, 2023, [pubmed.ncbi.nlm.nih.gov/36271471](https://pubmed.ncbi.nlm.nih.gov/36271471/)) randomized 84 participants 3:1 to once daily palopegteriparatide, starting at 18 mcg a day, or placebo, with both groups continuing conventional therapy for 26 weeks.

The primary endpoint set a high bar. To count as a success, a participant needed normal albumin adjusted serum calcium (8.3 to 10.6 mg/dL) at week 26, independence from conventional therapy (no active vitamin D and 600 mg/d or less of calcium), and no increase in study drug dose over the 4 weeks before week 26. At week 26, 79% (48/61) of participants on palopegteriparatide met that endpoint compared with 5% (1/21) on placebo, and 93% (57/61) of the palopegteriparatide group had achieved independence from conventional therapy.

Participants on palopegteriparatide also improved on every key secondary score of the Hypoparathyroidism Patient Experience Scale and on the SF-36 Physical Functioning subscale compared with placebo, and their mean 24 hour urine calcium normalized. Adverse events were reported by 82% (50/61) of the palopegteriparatide group and 100% (21/21) of the placebo group, most of them mild (46%) or moderate (46%), and no one withdrew because of the study drug.

In the trial population, the results held up at one year. After the blinded period, everyone in PaTHway moved to open label palopegteriparatide for a 156 week extension. The 52 week report (Clarke and colleagues, Journal of Clinical Endocrinology and Metabolism, 2025, [doi.org/10.1210/clinem/dgae693](https://doi.org/10.1210/clinem/dgae693)) covered 82 adults who were randomized and received study drug, of whom 78 completed week 52.

At week 52, 81% (63/78) met the multicomponent endpoint of normal serum calcium plus independence from conventional therapy, 95% (74/78) were independent from conventional therapy, and none of them needed active vitamin D. Mean 24 hour urine calcium fell from 376 mg/day at baseline to 195 mg/day, and no adverse event led to discontinuation during the open label extension. Across both trials, the share of people off conventional therapy stays between 91% and 95% from week 26 onward, although the later time points come from open label follow up without a placebo group.

A post hoc analysis of PaTHway found that kidney function, measured as estimated glomerular filtration rate (eGFR), went up over a year on palopegteriparatide. Rejnmark and colleagues (Advances in Therapy, 2024, [doi.org/10.1007/s12325-024-02843-8](https://doi.org/10.1007/s12325-024-02843-8)) reported a mean increase of 9.3 mL/min/1.73 m2 over 52 weeks, with 43% of participants gaining 10 mL/min/1.73 m2 or more. In people whose baseline eGFR was below 60, the mean gain was 11.5 mL/min/1.73 m2.

You should read that finding with two cautions in mind. The analysis was post hoc, meaning the question was asked after the trial had been designed, and there was no placebo comparison over the full year. The authors themselves concluded that "further investigation of palopegteriparatide for the preservation of renal function in hypoparathyroidism is warranted," so the kidney result is promising rather than established.

Bone density tends to drift down on palopegteriparatide, but it usually starts from a point that is higher than it should be. People with long standing hypoparathyroidism often have low bone turnover and bone density above what is typical for their age, because PTH is not there to drive normal remodeling.

In the 52 week PaTHway report, mean bone mineral density Z scores decreased toward age and sex matched norms. The 3 year PaTH Forward analysis found the largest drop during the first 26 weeks and modest declines after that, and mean Z scores at week 162 "remained above zero for all 4 sites." Bone turnover markers rose early and then settled, which the authors interpreted as the skeleton returning toward its natural state. Fracture outcomes over the long term have not been established in trials of this population.

Yorvipath is taken as a single subcutaneous injection each day. According to the FDA label, the recommended starting dosage is 18 mcg once daily, adjusted in 3 mcg increments or decrements, with a maximum recommended dosage of 30 mcg once daily. The goal is normal serum calcium without active vitamin D or therapeutic calcium doses, which the label defines as elemental calcium above 600 mg/day, although calcium that simply meets normal dietary needs can continue.

The label adds several practical rules. You use only one injection to reach the daily dose, because using two injections "increases the variability of the total delivered dose" along with the risk of unintended high or low calcium. Serum calcium is measured 7 to 10 days after the first dose and after dose changes, then periodically. The titration scheme was only evaluated in adults who first reached an albumin corrected serum calcium of at least 7.8 mg/dL on calcium and active vitamin D, and the drug was not studied for acute postsurgical hypoparathyroidism.

Lab monitoring sits at the center of this treatment, and our guide to [blood work on a peptide protocol](https://www.peptidepeppers.com/articles/peptide-protocol-blood-work-biomarker-monitoring) explains why calcium, kidney and other markers matter for anyone tracking a hormone therapy.

The most common side effects in the trials were injection site reactions, dizziness type symptoms and headache. The adverse reaction table on the label comes from the 26 week blinded period of PaTHway, with 61 people on Yorvipath and 21 on placebo, and it lists injection site reactions in 39% versus 5%, vasodilatory signs and symptoms in 28% versus 0, and headache in 21% versus 10%.

Vasodilatory signs and symptoms is a grouped label term that covers dizziness, a drop in blood pressure on standing, palpitations and fainting, and it connects directly to one of the warnings below.

The FDA label lists five warnings and precautions, which cover unintended calcium changes from using two injections, serious hypercalcemia and hypocalcemia, a potential risk of osteosarcoma, orthostatic hypotension and digoxin toxicity.

The osteosarcoma warning draws the most attention. The label states that Yorvipath "is not recommended in patients at increased risk of osteosarcoma," and it explains that osteosarcoma occurred more often in rats given PTH analogs including teriparatide, in a way that depended on dose and treatment duration, and that limited human data exist beyond 2 years of teriparatide use. This is a class concern carried over from animal studies of PTH drugs rather than a finding from the palopegteriparatide trials. For orthostatic hypotension, the label advises taking early doses where you can sit or lie down.

Early U.S. data suggest that the trial results carry over to patients treated in clinics. An analysis of the U.S. expanded access program (Graham and colleagues, Endocrine Practice, 2025, [doi.org/10.1016/j.eprac.2025.08.008](https://doi.org/10.1016/j.eprac.2025.08.008)) included 123 of the 135 patients who received at least one dose. Most of them (95.1%) had used shorter acting PTH therapy before, 50.4% switched directly, and treatment started at 18 mcg a day.

Over up to 12 months, the share of patients who were independent from conventional therapy rose, mean serum calcium stayed in range, and "no new safety signals were identified." Because this was an uncontrolled analysis supported by the manufacturer, it confirms that the drug is workable in practice more than it measures the size of the effect.

Palopegteriparatide is a prescription hormone replacement for a diagnosed endocrine disease, and it is dosed against frequent calcium labs rather than used as a bone, longevity or recovery peptide for healthy people. Nothing in the trials supports that kind of use, and giving PTH to someone whose parathyroid glands work normally would risk high calcium, which is one of the serious warnings on the label.

The bottom line for peptide readers is a lesson in delivery engineering. Palopegteriparatide shows how the same PTH(1-34) sequence becomes a different drug once its release is stretched from a pulse into a steady signal, and in the PaTHway trial that change let 93% of participants stop conventional therapy by week 26. If you or someone you care for lives with hypoparathyroidism, the trial data are worth raising with an endocrinologist, who can weigh them against the label warnings and the lab monitoring the treatment requires.