Peptide

Parathyroid hormone (PTH 1-84)

Full-length copy of human parathyroid hormone. It was used for hypoparathyroidism, but its manufacturer stopped producing it in 2024.

Regulatory status

Approved (FDA / EMA)

Family

Full-length recombinant human parathyroid hormone

Scientific evidence

Moderate

Number of findings

Where it acts

Hormones and metabolism · Bones and muscles

Also known as

parathyroid hormone, rhPTH(1-84), Natpara, Natpar, Preotact

Regulatory status

FDA (US): Approved (2015, Natpara) for hypocalcemia due to hypoparathyroidism; manufacturing discontinued by the manufacturer at the end of 2024 (no longer marketed).

EMA (EU): Approved (2017, Natpar, conditional authorization) for chronic hypoparathyroidism; manufacturing discontinued in 2024 and withdrawal of the authorization planned for July 1, 2026. Previously, Preotact (2006) was authorized for postmenopausal osteoporosis and was withdrawn.

Dose

Start with 50 µg subcutaneously daily, adjusting according to calcium up to 25–100 µg/day (REPLACE trial and FDA Natpara label). It should no longer be started in new patients.

Safety

Hypocalcemia and hypercalcemia, cramps, tingling, headache, nausea. In rats it caused osteosarcoma. Abrupt discontinuation can cause severe hypocalcemia: switching to another treatment must be done with close calcium monitoring.

Interactions

With digoxin, calcium changes increase the risk of toxicity.

Effect by goal · level of evidence

Less need for calcium and vitamin D in hypoparathyroidism

improves Moderate RCT (AA) in people

53% vs 2%

REPLACE RCT with 134 adults over 24 weeks: 53% reduced oral calcium and active vitamin D by at least half while keeping calcium in range, versus 2% with placebo.

View the study (RCT) →

In depth

Where it acts

Hormones and metabolism, Bones and muscles

How it works

It is the complete 84-amino-acid parathyroid hormone. It raises blood calcium by releasing it from bone, increasing its reabsorption in the kidney, and activating vitamin D. In hypoparathyroidism it replaces the missing hormone.

What the evidence says

In people

Less need for calcium and vitamin D in hypoparathyroidism. REPLACE RCT with 134 adults over 24 weeks: 53% cut oral calcium and active vitamin D by at least half while keeping calcium in range, versus 2% with placebo. PubMed 24622413

References

PubMed 24622413

Information, not medical advice. Prescription or unapproved peptides should only be used under medical supervision.