The short answer
Avoid grapefruit and grapefruit juice while taking oral tacrolimus. Juice can raise tacrolimus exposure, including with an extended-release formulation. Taking the grapefruit at another time is not an established solution.
What this answer covers
Human studies mainly measured grapefruit juice. The advice to avoid both juice and whole grapefruit comes from tacrolimus product information; individual juice products can have very different effects.
- Supplement or preparation
- Grapefruit (Citrus paradisi)
- Medication ingredient
- tacrolimus
What did the transplant studies show?
A liver-transplant study found markedly different tacrolimus changes with two grapefruit juices. A newer study in 11 kidney recipients found 28% higher total exposure and a 73% higher peak with one 8-ounce glass of characterized juice and extended-release LCPT tacrolimus. Neither result supplies a safe juice brand.
Does extended release prevent the interaction?
The LCPT study shows that extended release can still interact with grapefruit juice. It did not compare the two release forms directly, so its size of effect should not be used to predict another tacrolimus product. Keep your prescribed formulation and follow its instructions.
Why does the advice include the fruit?
Although the measured studies used juice, the PROGRAF label tells patients to avoid grapefruit as well as its juice. Do not treat whole fruit as proven safe because a trial used a drink. The label does not offer a number of hours that makes the combination acceptable.
What if I have already had grapefruit?
Contact your transplant team with the amount, product and time consumed. They can decide whether tacrolimus levels or kidney function need checking. Excess exposure can increase toxicity, but the juice studies do not quantify your chance of kidney injury or infection. Keep taking tacrolimus as prescribed while obtaining advice.
Evidence and practical considerations
Absorption & effectiveness
Grapefruit juice increases oral tacrolimus exposure in human transplant studies, with product and formulation variability.
- Exact scope
- Citrus paradisi juice; whole fruit avoidance is label-based, not a measured fruit-trial effect. with Tacrolimus, exact RxCUI 42316, inventory name tacrolimus, TTY IN. Oral systemic tacrolimus only. The US PROGRAF label describes tacrolimus capsules and anhydrous-equivalent strength; the UK capsule SmPC section 2 explicitly states tacrolimus as monohydrate. This bridges labeled monohydrate capsules to the IN, without merging different release formulations or transferring exposure results to topical or intravenous tacrolimus. No cyclosporine or other immunosuppressant evidence is substituted for tacrolimus evidence.
- Medication form and route
- oral
What remains uncertain
- Small studies; effects differ by juice and release formulation.
Read the supporting source summaries
Source 1: original human clinical study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Thirty liver transplant recipients one month after surgery, three groups of ten.
The two juice groups had mean increases from baseline of 1.56 and 10.33 ng/mL. Only the larger-change group differed significantly from control; that group needed less tacrolimus.
How this applies: Direct human juice evidence, with product variability. Does not measure whole fruit or establish a safe juice brand.
Small short study with dose adjustment and markedly different juice effects. No quantified infection risk. Abstract-only access prevents full product and methods verification.
Source 2: original human clinical study
pmc.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Eleven stable adult kidney transplant recipients in a randomized crossover study; enrollment 2019-2021.
Tacrolimus 24-hour exposure was 28% higher, geometric ratio 1.28 (90% CI 1.12-1.44); peak concentration was 73% higher, ratio 1.73 (1.46-2.00).
How this applies: Direct for LCPT extended-release oral tacrolimus. Demonstrates that extended release does not remove the juice interaction; other oral formulations retain their own label precautions.
One characterized juice and small stable-transplant sample. It did not directly compare immediate-release with extended-release products and did not test whole fruit or sustained clinical toxicity.
Research assessment: · Open full citations ↗
Timing & monitoring
Tacrolimus labeling supports avoiding grapefruit fruit and juice, rather than substituting a spacing interval.
- Exact scope
- Whole grapefruit and grapefruit juice, oral consumption. with Tacrolimus, exact RxCUI 42316, inventory name tacrolimus, TTY IN. Oral systemic tacrolimus only. The US PROGRAF label describes tacrolimus capsules and anhydrous-equivalent strength; the UK capsule SmPC section 2 explicitly states tacrolimus as monohydrate. This bridges labeled monohydrate capsules to the IN, without merging different release formulations or transferring exposure results to topical or intravenous tacrolimus. No cyclosporine or other immunosuppressant evidence is substituted for tacrolimus evidence.
- Medication form and route
- oral
What remains uncertain
- No measured universally safe quantity or timing schedule.
Read the supporting source summaries
Source 1: regulatory prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients receiving systemic tacrolimus for transplant immunosuppression; oral capsules and granules discussed separately from injection.
Requires drug-level monitoring and individualized dosing. Warns of nephrotoxicity, infections, neurotoxicity, QT prolongation and hyperkalemia. Avoid grapefruit and juice; CBD needs close monitoring and possible dose reduction.
How this applies: Medication-specific safety and monitoring context. Additional supplement-specific findings and explicit formulation boundaries are required.
Label warnings do not quantify the added clinical-event risk from each supplement. The oral products are not freely interchangeable; topical use is outside these data.
Research assessment: · Open full citations ↗
Side effects & toxicity
Grapefruit-related excess tacrolimus exposure can increase toxicity concern; measured kidney-injury and infection rates are unavailable.
- Exact scope
- Grapefruit juice; fruit warning through label. with Tacrolimus, exact RxCUI 42316, inventory name tacrolimus, TTY IN. Oral systemic tacrolimus only. The US PROGRAF label describes tacrolimus capsules and anhydrous-equivalent strength; the UK capsule SmPC section 2 explicitly states tacrolimus as monohydrate. This bridges labeled monohydrate capsules to the IN, without merging different release formulations or transferring exposure results to topical or intravenous tacrolimus. No cyclosporine or other immunosuppressant evidence is substituted for tacrolimus evidence.
- Medication form and route
- oral
What remains uncertain
- Clinical consequences inferred from exposure and medication label, not quantified in the small PK trials.
Read the supporting source summaries
Source 1: regulatory prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients receiving systemic tacrolimus for transplant immunosuppression; oral capsules and granules discussed separately from injection.
Requires drug-level monitoring and individualized dosing. Warns of nephrotoxicity, infections, neurotoxicity, QT prolongation and hyperkalemia. Avoid grapefruit and juice; CBD needs close monitoring and possible dose reduction.
How this applies: Medication-specific safety and monitoring context. Additional supplement-specific findings and explicit formulation boundaries are required.
Label warnings do not quantify the added clinical-event risk from each supplement. The oral products are not freely interchangeable; topical use is outside these data.
Source 2: original human clinical study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Thirty liver transplant recipients one month after surgery, three groups of ten.
The two juice groups had mean increases from baseline of 1.56 and 10.33 ng/mL. Only the larger-change group differed significantly from control; that group needed less tacrolimus.
How this applies: Direct human juice evidence, with product variability. Does not measure whole fruit or establish a safe juice brand.
Small short study with dose adjustment and markedly different juice effects. No quantified infection risk. Abstract-only access prevents full product and methods verification.
Source 3: original human clinical study
pmc.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Eleven stable adult kidney transplant recipients in a randomized crossover study; enrollment 2019-2021.
Tacrolimus 24-hour exposure was 28% higher, geometric ratio 1.28 (90% CI 1.12-1.44); peak concentration was 73% higher, ratio 1.73 (1.46-2.00).
How this applies: Direct for LCPT extended-release oral tacrolimus. Demonstrates that extended release does not remove the juice interaction; other oral formulations retain their own label precautions.
One characterized juice and small stable-transplant sample. It did not directly compare immediate-release with extended-release products and did not test whole fruit or sustained clinical toxicity.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Original evidence and current product information inspected; article distinguishes observed results, product limits and remaining uncertainty. | |
| Research summary published |
Article revision: 392015b155e44d7a
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.