Herbs, Immunosuppressants and Organ Transplants
Why people on transplant or other immune-suppressing medicines should ask their transplant team before any herb: St. John's wort and cyclosporine, echinacea, tacrolimus and what reviews found.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
If you have had an organ transplant, talk to your transplant team before starting, stopping or changing any herb, tea or supplement. Do not stop an anti-rejection medicine on your own. A herb that lowers the blood level of such a medicine could, in the worst case, contribute to rejection, and a herb that raises it could cause toxicity. A recent review of herbs and transplant medicines describes both risks. [1]
What the sources found
| Herb | What the source found | Strength of evidence |
|---|---|---|
| St. John's wort | Reduced blood cyclosporin levels, suggested by multiple case reports and by clinical trials. [6] Later research showed it altered the levels of other drugs including tacrolimus. [5] A tacrolimus review says CYP3A4 inducers such as St. John's wort may reduce the drug concentration and so its effect. [7] | Documented (reviews, case reports and trials) |
| Echinacea (Echinacea purpurea (L.) Moench and related species) [8] | NCCIH says there are theoretical reasons to suspect that echinacea might interact with immunosuppressants. It also notes conflicting evidence on liver-processed drugs. [9] | Theoretical; Proper evidence not found for rejection or toxicity in the pages we read |
| Ginger and turmeric | A tacrolimus review lists ginger and turmeric, with grapefruit, pomelo, clementine and pomegranate, among CYP3A4 inhibitors that can raise tacrolimus levels, revealing the drug's side effects, particularly nephrotoxicity. [7] | Narrative review; based on mechanism and limited reports |
| Panax ginseng, green tea, Schisandra sphenanthera | The same review calls the use of these with tacrolimus highly controversial. [7] | Mixed |
| Grapefruit (a food, for comparison) | MedlinePlus advises avoiding grapefruit juice or grapefruit with cyclosporine. [4] | MedlinePlus drug information |
The tacrolimus review drew on searches of PubMed, Scopus and Cochrane; it is a review of the literature, not a new trial. It notes that tacrolimus is metabolized in the liver by CYP3A4 and has a narrow therapeutic window. [7]
Contamination and kidneys
The recent review of kidney transplant recipients notes that contamination of herbal preparations with heavy metals poses an additional risk, because nephrotoxic metals have been linked to graft dysfunction. [1] Product quality is covered on heavy metals, pesticides and microbes in herbal products.Other immune-suppressing situations
This page is mostly about transplant medicines because that is where the sources are. For autoimmune conditions and immune-stimulating herbs, see herbs and autoimmune conditions and our safety guide on autoimmune conditions and immune-stimulating products. Proper evidence not found in the pages we read for interactions between specific herbs and steroid or biologic regimens used to suppress the immune system.What you can do
- Keep a written list of every medicine, herb and supplement and show it at each transplant visit. MedlinePlus advises this for people taking cyclosporine. [4] Our medicine and supplement worksheet is one format.
- Ask the transplant team or pharmacist before trying any new herb or tea. NCCIH says strong evidence to back up claims made for dietary supplements is often lacking, so an "immune support" label is not a safety label. [10] See herbs for immune support: claims checked.
- Read broader guidance: supplements and immunosuppressants and transplant medicines.
Limits
Our sources are reviews and drug information pages. We did not read a trial of echinacea in transplant recipients, and the interaction reports for ginger and turmeric come from a review of mechanisms and limited data. Not seeing a herb listed is not evidence that it is safe.Frequently asked questions
Can transplant patients take St. John's wort?
NCCIH and MedlinePlus both name cyclosporine as a medicine St. John's wort can interact with. [3][4] Ask your transplant team; do not decide alone.
Is echinacea safe with immunosuppressants?
NCCIH describes a theoretical reason to suspect an interaction. [9] Proper evidence not found, in the pages we read, for a documented case. Ask your transplant team.
Does grapefruit matter?
MedlinePlus advises avoiding grapefruit juice or grapefruit while taking cyclosporine. [4] A tacrolimus review also lists grapefruit as a CYP3A4 inhibitor. [7]
Can herbal products be contaminated?
The review of kidney transplant recipients notes heavy metal contamination as an additional risk. [1] See adulteration and substitution of herbs.
What should I do if I already take a herb?
Do not stop your anti-rejection medicine. Tell your transplant team about the herb promptly, bring the label, and ask whether to continue. A pharmacist can also help. [4]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Pregnancy, breastfeeding, children
References
- Santana L, et al. Herb-immunosuppressive drug interactions: implications for kidney transplant recipients. Fitoterapia 2026 (narrative review); PubMed abstract. Read 2026-10-23.
- GBIF Secretariat, GBIF Backbone Taxonomy match for Hypericum perforatum: accepted name Hypericum perforatum L.. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NCCIH, US), St. John's Wort, last updated May 2025. Read 2026-10-23.
- MedlinePlus, Cyclosporine, drug information page. Read 2026-10-23.
- Nicolussi S, Drewe J, Butterweck V, Meyer Zu Schwabedissen HE. Clinical relevance of St. John's wort drug interactions revisited. British Journal of Pharmacology 2020 (review; some authors are employees of a St. John's wort product manufacturer); PubMed abstract. Read 2026-10-23.
- Borrelli F, Izzo AA. Herb-drug interactions with St John's wort (Hypericum perforatum): an update on clinical observations. AAPS Journal 2009; PubMed abstract. Read 2026-10-23.
- Miedziaszczyk M, et al. Controversial interactions of tacrolimus with dietary supplements, herbs and food. Pharmaceutics 2022; PubMed abstract. Read 2026-10-23.
- GBIF Secretariat, GBIF Backbone Taxonomy match for Echinacea purpurea: accepted name Echinacea purpurea (L.) Moench. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NCCIH, US), Echinacea, last updated November 2024. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NCCIH, US), Using Dietary Supplements Wisely, last updated January 2019. Read 2026-10-23.