Cyclosporine
Cyclic peptide immunosuppressant
Also Ciclosporin, Cyclosporin, Cyclosporin A, Sandimmune, Neoral, Gengraf
- Evidence
- AStrong human evidence
- FDA status
- FDA approvedas of 2026-10-26
- Route
- Several routes
- Studies cited
- 1 human0 animal or cell
It is a drug that calms the immune system so the body does not reject a transplanted organ. A 1983 trial of 209 kidney recipients showed more transplants survived the first year.
Sold for
Cyclosporine is not sold as a wellness peptide; its reputation is as the drug that made organ transplantation routine, and its online discussion is mostly patients comparing it with tacrolimus or asking about the eye drops.
Studies say
A randomized trial in 1983 showed a 16-percentage-point gain in one-year kidney graft survival, and the drug's approval and decades of use rest on that class of evidence, which is an A.
Why grade A. The transplant use was established by randomized trials, including the Canadian Multicentre Transplant Study in the citations, which randomized 209 recipients of cadaveric kidneys and found one-year graft survival of 80% with cyclosporine against 64% with azathioprine and prednisone. Forty years of subsequent trials and registry data confirm it. 12
FDA. Cyclosporine is FDA-approved: Sandimmune (1983) for preventing rejection of kidney, liver and heart transplants; Neoral and generics for transplant rejection, rheumatoid arthritis and psoriasis; and Restasis eye drops (2002) for increasing tear production in dry eye. The systemic products carry boxed warnings for immunosuppression-related infection and malignancy, kidney toxicity and hypertension. 234
Written from 4 cited sources. Fact-checked 2026-10-27: 12 claims checked, 0 corrected. Last refreshed 2026-10-27. Not physician reviewed.
What this means for you
- What people take it for
- Preventing transplant rejection, and some arthritis, skin and dry eye problems
- Can a US doctor prescribe it?
- Yes, FDA approved for preventing transplant rejection, rheumatoid arthritis, psoriasis and dry eye.
- Properly tested in people?
- Yes, in large controlled trials. The key trial had 209 people.
Evidence checklist
- Randomised controlled trial Canadian Multicentre Transplant Studyyes
- Human study over 100 people 209 kidney transplant recipientsyes
- More than one research group Four decades of trials and registry datayes
- Clinical outcomes, not surrogate markers Graft survival 80% vs 64% at one yearyes
- Human safety data beyond case reports Boxed warnings; decades of use and monitoringyes
Drawn from the cited studies below. A dash means the sources give no information.
What it is
Cyclosporine is a ring-shaped peptide of 11 amino acids. A soil fungus, Tolypocladium inflatum, makes it. Several of its amino acids are unusual, and it is heavily methylated. That makes it fat-soluble. It can cross cell membranes in a way most peptides cannot. People take it by mouth or get it intravenously for whole-body use. It also comes as eye drops for dry eye. 24
Sandoz isolated it in the early 1970s. The FDA approved Sandimmune in November 1983. Neoral followed in 1995. It is a microemulsion with more predictable absorption. Generic versions of both are available. Restasis is a low-concentration eye emulsion. It was approved in December 2002. 234
How it works
Inside T lymphocytes, cyclosporine binds a protein called cyclophilin. The complex blocks calcineurin. T cells need this enzyme to switch on the gene for interleukin-2. Without interleukin-2, T cells do not multiply in response to foreign tissue. So the immune attack on a transplanted organ is damped. Other parts of the immune system keep working. The same calcineurin block in the eye reduces T-cell-driven inflammation. That inflammation suppresses tear production in dry eye. 24
What human research shows
The Canadian Multicentre Transplant Study Group randomized 209 recipients of cadaveric kidneys. One group got cyclosporine plus prednisone. The other got the standard regimen of azathioprine plus prednisone. Predicted one-year graft survival was 80.4% with cyclosporine and 64.0% with standard therapy. One-year patient survival was 96.6% against 86.4%. Grafts did worse in the cyclosporine group when the kidney had been machine-perfused for over 24 hours. This was an early sign of the drug's kidney toxicity. 1
The labels summarize later controlled trials. These covered liver and heart transplantation, rheumatoid arthritis and severe psoriasis. For Restasis, two multicentre trials found a measurable rise in tear production at six months. More patients had it than with the vehicle alone. 234
| Study | Model | Finding |
|---|---|---|
| Canadian Multicentre Transplant Study | Humans, n=209 cadaveric kidney recipients, randomized controlled | One-year graft survival 80.4% with cyclosporine versus 64.0% with azathioprine and prednisone; patient survival 96.6% versus 86.4%. 1 |
| Sandimmune prescribing information | Regulatory summary of transplant trials | Approved for kidney, liver and heart transplant rejection prophylaxis; boxed warnings for immunosuppression and nephrotoxicity. 2 |
| Restasis prescribing information | Humans, two multicentre vehicle-controlled trials in dry eye | More patients had increased tear production at six months than with vehicle. 4 |
Safety
Systemic cyclosporine carries boxed warnings. It raises the risk of serious infection. It also raises the risk of cancers, especially lymphoma and skin cancer, because it suppresses immune surveillance. It is toxic to the kidney, and the harm depends on the dose. It raises blood pressure. Other common effects are tremor, excess hair growth and gum overgrowth. It can also cause high potassium, high lipids and raised blood sugar. Doctors must monitor blood levels. Absorption varies, and many drugs change its metabolism, including grapefruit juice. 23
Restasis eye drops deliver very little drug to the bloodstream. The main complaint is burning on instillation. 4
Questions for your clinician
- Which blood tests will track the kidney and blood pressure effects?
- Which of my other medicines or foods change cyclosporine levels?
- How is infection and cancer risk watched during long use?
Questions people ask
Is cyclosporine FDA-approved?
Yes. Sandimmune was approved in 1983 for transplant rejection. Neoral followed in 1995, with added uses in rheumatoid arthritis and psoriasis. Restasis eye drops were approved in 2002 for dry eye. 234
Is cyclosporine really a peptide?
Yes. It is a ring-shaped peptide of 11 amino acids, made by a fungus. Its unusual, methylated amino acids make it fat-soluble. That is why people can take it by mouth when most peptides cannot. 2
What are the main risks?
Kidney damage and high blood pressure are the main ones. Suppressing T cells also brings infections and cancers. All of these carry boxed warnings on the whole-body products. Blood-level monitoring is standard. The eye drops mostly cause burning on application. 234
How does it compare with tacrolimus?
Both block calcineurin. Tacrolimus has become the more common first choice in transplantation. The 1983 trial compared cyclosporine with azathioprine, not tacrolimus. So the citations here do not answer the head-to-head question. 1
Citations
- Canadian Multicentre Transplant Study Group 1983, NEJM: randomised trial of cyclosporine in cadaveric renal transplantation doi.org
- Sandimmune (cyclosporine) prescribing information drugs.com
- Neoral (cyclosporine modified) prescribing information drugs.com
- Restasis (cyclosporine ophthalmic emulsion) prescribing information drugs.com