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Legal status · Australia

Is Relaxin-2 legal in Australia?

Written by Reviewed Sep 2026

Not approvedHormoneHuman studies cited: 3

Direct answer

No. Relaxin-2 is not an approved medicine in Australia; its classification is "Not a medicine; endogenous signalling molecule". Nothing containing it is authorized for any use in people. Vials labeled "for research use only" are not exempt: that label does not make human use lawful. On the evidence, 3 human studies are cited on its profile.

Relaxin-2 in Australia at a glance

ClassificationNot a medicine; endogenous signalling molecule
NoteNo registered relaxin medicine.
TGA approval statusNot approved by TGA
Human studies cited3 of 5 citations on the profile
ReviewedSep 2026

Classification and note come from the Relaxin-2 profile, checked against Therapeutic Goods Administration (TGA) listings at the reviewed date.

What this means

  • 01

    No product containing Relaxin-2 is approved by TGA for any use in Australia, so nothing on the market is authorized for people.

  • 02

    "Research use only" is a vendor label, not a legal category that permits human use. It does not exempt a product from medicines law.

  • 03

    Importing, supplying or promoting it for human use can fall under medicines legislation in Australia. This page is general information, not legal advice.

What Relaxin-2 is

The pregnancy hormone that opens the circulation. A 1,161 patient phase 3 trial reported 42 deaths against 65 on placebo at 180 days as an additional endpoint, and the 6,545 patient confirmatory trial found cardiovascular death of 8.7 percent against 8.9 percent, hazard ratio 0.98. Serelaxin was never approved and development for acute heart failure stopped.

Relaxin-2 is a two-chain peptide hormone of the insulin superfamily, made by the corpus luteum and the placenta, and it is the reason a pregnant woman's cardiac output rises and her blood vessels and kidneys relax. That physiology is not in question and it is a perfectly good reason to have wondered whether the same hormone could help a failing heart.

Mechanism: Relaxin-2 acts at RXFP1, a G protein-coupled receptor, and produces systemic vasodilation, increased cardiac output, increased renal blood flow and increased arterial compliance, largely through nitric oxide and cyclic AMP dependent pathways, together with anti-fibrotic signalling that has been the focus of most later work. It is a two-chain molecule held together by disulfide bonds, built like insulin, which is why it is hard and expensive to manufacture and why simplified single-chain analogues were designed.

Regulatory history: Relaxin-2 is an endogenous hormone. Serelaxin, its recombinant form, is not approved by the FDA or any other regulator. It received attention after the RELAX-AHF result but the confirmatory RELAX-AHF-2 trial failed both primary endpoints and development for acute heart failure was discontinued.

How TGA treats this kind of product

Registers or lists therapeutic goods on the ARTG and schedules substances in the Poisons Standard. Many peptides are Schedule 4 (prescription only), so possession without a prescription and personal importation are restricted even when no product is registered.

The classification above is the The Longevity Archive reading of Therapeutic Goods Administration listings for Relaxin-2 at the reviewed date, not a legal opinion. Rules change, and importing, prescribing and possessing a compound can each be treated differently. Check the regulator directly before acting on anything here.

Relaxin-2 in other countries

Frequently asked questions

Is Relaxin-2 legal in Australia?

No. Relaxin-2 is not an approved medicine in Australia; its classification is "Not a medicine; endogenous signalling molecule". Nothing containing it is authorized for any use in people. Vials labeled "for research use only" are not exempt: that label does not make human use lawful. On the evidence, 3 human studies are cited on its profile. Note: No registered relaxin medicine.

Can I buy Relaxin-2 in Australia?

No approved product exists to buy. In Australia Relaxin-2 is classified as "Not a medicine; endogenous signalling molecule", so there is no licensed pharmacy product. Vendors selling it "for research use only" are not selling it for human use, and that label does not change its legal status. This site does not list or recommend vendors. Note: No registered relaxin medicine.

Is Relaxin-2 TGA approved?

No. In Australia Relaxin-2 is classified as "Not a medicine; endogenous signalling molecule", which is not a TGA marketing approval. For comparison, the US FDA status is: Relaxin-2 is an endogenous hormone. Serelaxin, its recombinant form, is not approved by the FDA or any other regulator. It received attention after the RELAX-AHF result but the confirmatory RELAX-AHF-2 trial failed both primary endpoints and development for acute heart failure was discontinued.. On the evidence, 3 human studies are cited on its profile.

Related compounds in Australia

Full research profile

Mechanism, cited studies, FDA status and the full legal summary for Relaxin-2 live on its compound profile.

Relaxin-2 profile

This page is general information about the regulatory status of Relaxin-2 in Australia, current as of Sep 2026. It is not legal advice, and classifications change; check Therapeutic Goods Administration directly or consult a lawyer for a specific situation. Educational use only. This database summarizes published research. It is not medical advice and contains no dosing protocols or recommendations for personal use. The Longevity Archive has no vendor relationships and does not recommend where to buy anything.