Immune & antimicrobial

Cyclosporine

Also called ciclosporin, cyclosporin A, Sandimmune, Neoral, Gengraf, Restasis, Vevye

Cyclosporine is a ring-shaped peptide made by a soil fungus. It calms the immune system and changed organ transplantation in the 1980s; it is also used for rheumatoid arthritis, psoriasis and, as eye drops, dry eye.

FDA-approvedApproved by the FDA for at least one use after large human trials.

All printable flashcards

Drawn from its published sequence: 11 residues, one bead each. Dashed arcs are ring bonds.

Overview

How it works

Established: cyclosporine enters T cells and binds a protein called cyclophilin. Together they block calcineurin, an enzyme needed to switch on the NFAT transcription factor. Without NFAT, T cells make much less IL-2 and other activating signals, so the immune attack (for example, on a transplanted organ) is damped. It also binds cyclophilin D in mitochondria.

What research shows

Early kidney (Calne et al., Lancet 1978) and liver (Starzl et al., NEJM 1981) transplant series established its role in preventing rejection.
Kidney toxicity is a major limit of long-term use (Naesens et al., Clin J Am Soc Nephrol 2009 review).
A Cochrane review linked cyclosporine to raised blood pressure in transplant and autoimmune patients (Robert et al., 2010).

Doses studied in people

Doses are individualized by indication, body weight and blood-level monitoring per the FDA labels (Sandimmune, Neoral, Restasis); the label doses could not be opened and re-verified for this entry, so none are listed here.

Read this first: these are the amounts given to participants in published studies or written on official prescribing labels, reported for reference. They are not recommendations. Trial doses were chosen for specific patients under medical supervision, and a dose that is safe in one person can be harmful in another.

Safety

Systemic products (Sandimmune, Neoral and generics) carry FDA boxed warnings; see the current DailyMed labels for exact wording (not re-verified in this pass).
Kidney toxicity and high blood pressure are common and dose-related (Naesens 2009; Robert 2010).
Other: excess hair growth, gum overgrowth, high potassium, high uric acid/gout, high cholesterol, tremor, headache.
Many drug interactions through CYP3A4 and P-glycoprotein; blood levels need monitoring.

Report side effects of any drug or product to the FDA through MedWatch. For a possible poisoning in the US, call Poison Control at 1-800-222-1222.

Legal status

FDA: FDA-approved (Sandimmune, 1983; Neoral and generics) for prevention of organ rejection, and Neoral/generics for severe rheumatoid arthritis and psoriasis; ophthalmic emulsions (Restasis, Vevye) for dry eye.
Compounding: FDA-approved drug; ophthalmic compounding exists but is not equivalent to approved products.
Sports (WADA): Not named on the 2026 WADA Prohibited List.
Other: Prescription only.

Rules change often. See Legal status of peptides for how these categories work.

History

Sandoz scientists isolated the fungus from soil samples around 1970-71, and Hartmann Stähelin found its immune-suppressing effect in 1972. Borel and colleagues published its biology and the structure was solved in 1976. Calne showed success in kidney transplants in 1978, and the FDA approved it (Sandimmune) in 1983. A better-absorbed microemulsion (Neoral) and Restasis eye drops (2002) followed.

Common questions

Is cyclosporine FDA-approved?

Yes. Sandimmune, Neoral and generics are approved to prevent organ rejection, and Neoral and generics also for severe rheumatoid arthritis and psoriasis ¹². The systemic products carry FDA boxed warnings, the strongest kind of label warning ¹².

How was cyclosporine discovered?

Sandoz scientists isolated it from a soil fungus in the early 1970s and found its immune-calming effect in 1972 ⁸. Borel and colleagues described its biology in 1976 ⁴.

How does cyclosporine calm the immune system?

Inside T cells it binds a protein called cyclophilin, and together they block calcineurin, an enzyme T cells need to switch on ³. The T cells then make much less IL-2 and other signals that drive an immune attack ³.

What does the research show?

Early kidney transplant results in 1978 and liver transplant results in 1981 established its role in preventing organ rejection ⁵⁹.

What are the main risks?

Kidney damage is a major limit of long-term use ⁶. A Cochrane review also linked it to raised blood pressure in transplant and autoimmune patients ⁷.

Is cyclosporine banned in sport?

It is not named on WADA's 2026 Prohibited List ⁹⁰.

Related compounds

Infection & antiviralFDA-approvedFlashcard

Daptomycin

Cubicin · Cubicin RF

Daptomycin is an antibiotic made by soil bacteria.

Sources

Last reviewed 2026-10-25 · How we research · Found an error? See our corrections policy.