@ca426
You will find more information in The Journal of Renal Nutrition from a study conducted by Linda Moore et. al. We are so blessed as a transplant community to have such amazing scientists researching on our behalf. The study looks at supplements and herbal remedies including but not limited to:

Vitamin C
St. John’s Wort
Herbal teas: green tea, chamomile, peppermint, dandelion...
Echinacea
Dong quai
Ginseng
Feverfew

Here is a portion of the article which I will cite below as well as a link to the Journal of Renal Nutrition:

"More research is needed regarding how transplant recipients could safely incorporate any of these products into their lifestyle. Until then, clinical teams should help transplant patients understand that these products will affect how their bodies absorb, distribute, metabolize, and excrete the antirejection drugs and could affect the outcome of graft survival."

1. Moore LW. Food, food components, and botanicals affecting drug metabolism in transplantation. J Ren Nutr. 2013 May;23(3):e71-3. doi: 10.1053/j.jrn.2013.02.002. PubMed PMID: 23611558
https://www.jrnjournal.org/article/S1051-2276(13)00061-7/fulltext
Foods known to interact with transplant meds are: grapefruit, grapefruit juice, pomegranate, Seville oranges.