Drug & supplement interaction

Theacrine + Tacrolimus

Tacrolimus brand names: Prograf (capsule), Prograf (injectable), Protopic, Prograf XL, Astagraf XL, and others.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Theacrine and Tacrolimus in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Theacrine and Tacrolimus

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Tacrolimus and Theacrine in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Theacrine safety at a glance

Theacrine overall Use caution Short-term use appears generally well tolerated in studies, but long-term safety is not well established.
Pregnancy Avoid Not enough safety data, so avoid use during pregnancy.
Breastfeeding Avoid Not enough safety data, so avoid use while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Tacrolimus and Theacrine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Tacrolimus

Interactions in our licensed database are recorded against drug classes, not just single drug names. Tacrolimus is filed under 8 classifications — including immunosuppressants, qt interval-prolonging drugs, topical drugs. Theacrine has documented interactions with 1 drug class — the most serious being cns depressants (moderate) — and none of Tacrolimus’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Theacrine Does Interact With Other Medications

Theacrine has 248 moderate known drug interactions in our database — Tacrolimus isn’t one of them. If you take anything else, check it against the full list below.

Moderate 248 No known interaction 2,582 (incl. Tacrolimus)
Taking anything else?

Check Another of Your Medications Against Theacrine

Covers the 2,830 medications we’ve checked against Theacrine. Pick one to open its full report.

What to actually watch for

What Tacrolimus’s Own FDA Label Lists

This is not an interaction — none of it involves Theacrine. These are the most notable effects listed in the ADVERSE REACTIONS section of Tacrolimus’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • Loss of vision Worth acting on
  • Low magnesium Worth acting on
  • Hearing loss Worth acting on
  • A stroke or mini-stroke Worth acting on
  • A bowel blockage Worth acting on
  • Bone thinning Worth acting on
  • Pain or burning when passing urine Worth acting on
  • Memory problems Worth acting on
  • Dehydration Worth acting on
  • Trouble swallowing Worth acting on

Showing the 10 most notable of 87 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Tacrolimus. Read the label on DailyMed › Where a percentage is shown, it is the share of 152,391 voluntary FDA FAERS reports for Tacrolimus that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Theacrine’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Theacrine side to compare — that is a limit of the record, not a statement that Theacrine has no side effects.

From our Q&A

Questions About Theacrine or Tacrolimus

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Theacrine or Tacrolimus, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Tacrolimus

This page covers Theacrine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tacrolimus page lists 202 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Asarabacca (major) and Cesium (major).

By severity: 11 major · 152 moderate · 39 minor.

From our pharmacist’s overview on the Tacrolimus page

“Tacrolimus (Prograf, Astagraf XL, Envarsus XR) keeps a transplanted organ from being rejected, and it works inside a narrow blood-level window, meaning even small shifts can invite rejection or toxicity. That makes these 202 supplement interactions worth real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Tacrolimus interaction page

One more smart check

Taking Theacrine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 501 real supplement products containing Theacrine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Theacrine. Even though Theacrine itself has no known interaction with Tacrolimus, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Theacrine and Tacrolimus Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Theacrine
Top 25%

#244 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Tacrolimus
Top 10%

#241 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Theacrine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Theacrine and Tacrolimus records this page draws on were last updated June 20, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Theacrine

What is Theacrine?

  • Energy and reduced fatigue
  • Focus and mental alertness
  • Mood support
  • Pre-workout performance
  • Caffeine-like stimulation with possibly less tolerance

Theacrine is a caffeine-like compound found naturally in certain tea plants and is sold in supplements for energy, focus, and mood. Early human studies suggest it may give a stimulant-like boost, but the overall evidence is limited and long-term safety is not well known. Talk with your pharmacist or doctor before using it, especially if you are sensitive to stimulants or have heart problems.

Leaves (and a synthetic version is also made) · Capsules, tablets, powders (often in pre-workout and energy blends)

An interaction check asks whether these two react with each other — it does not ask whether Theacrine is a good idea for someone in your situation. Here is what our Theacrine record says about it on its own.

Theacrine: dosing

There is no officially established or standardized dose for theacrine. Amounts used in supplements vary, and it is often combined with caffeine and other ingredients in blends.The safest approach is to follow the directions on the product label and not exceed the recommended amount. Avoid taking it close to bedtime so it does not interfere with sleep.

From our Theacrine monograph — the full record covers uses, side effects and every documented interaction.

Read the full Theacrine monograph & all interactions
Medication

About Tacrolimus

What Is Tacrolimus Used For?

Brand names: Prograf (capsule), Prograf (injectable), Protopic, Prograf XL, Astagraf XL, Envarsus XR

Tacrolimus is prescribed to help prevent your body from rejecting a transplanted organ. It is used in adults who receive a kidney, liver, or heart transplant, and in children who receive a liver transplant. It is always used alongside other anti-rejection medicines.

Because tacrolimus works by dampening your immune system, it lowers the risk of your body attacking the new organ — but it also means you need to be watched closely for infections and other side effects throughout your treatment.

Most-Reported Side Effects for Tacrolimus

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Acute kidney injury 6,154 reports
Diarrhea 5,965 reports
Transplant rejection 5,034 reports
Fever 4,886 reports
Cytomegalovirus infection 4,655 reports
See full Tacrolimus drug information
Keep checking

Other Drugs & Theacrine

Browse every other medication we’ve checked against Theacrine — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
248Moderate
0Minor
2,581No known interaction
248 Moderate 2,581 No interaction
Moderate

248 interactions

Showing 60 of 248 moderate interactions — see all 248 on the Theacrine page.

No interaction 2,581 drugs checked — show the list

We also checked Theacrine against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,581 medications checked with no known interaction — see the full Theacrine list.

See the full Theacrine interactions page
See every supplement checked against Tacrolimus, ranked by severity
Evidence & sources

Theacrine References

The 1 references that drive our Theacrine monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Xu JK, Kurihara H, Zhao L, Yao XS. Theacrine, a special purine alkaloid with sedative and hypnotic properties from Cammelia assamica var. kucha in mice. J Asian Nat Prod Res 2007;9(6-8):665-72.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Theacrine and Tacrolimus Together: Common Questions

Is it safe to take Theacrine with Tacrolimus?
We do not list a known interaction between Theacrine and Tacrolimus. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Theacrine and Tacrolimus combination checked?
Interactions in our licensed database are recorded against drug classes. Tacrolimus is filed under 8 classifications, and Theacrine has documented interactions with 1 drug class — none of Tacrolimus's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Theacrine interact with any other medications?
Yes. Theacrine has 248 documented drug interactions in our database — Tacrolimus is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Tacrolimus interact with any supplements?
Yes. Tacrolimus has documented interactions with 202 supplements in our database — Theacrine is not one of them. The Tacrolimus interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Theacrine monograph Uses, safety profile, and every drug interaction in one place Tacrolimus drug information The full plain-English guide to this medication Tacrolimus supplement interactions Every supplement checked against Tacrolimus, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Tacrolimus and Theacrine?

Our pharmacists answer your medication & supplement questions — free.

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.