Drug & supplement interaction

Alder Buckthorn + Voxelotor

Voxelotor brand name: Oxbryta.

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

We found no known interaction between Alder Buckthorn and Voxelotor 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

Alder Buckthorn and Voxelotor

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 Voxelotor and Alder Buckthorn 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.

Alder Buckthorn safety at a glance

Alder Buckthorn overall Use caution May relieve constipation short-term but can harm the bowel with regular or long-term use.
Pregnancy Avoid Stimulant laxatives like alder buckthorn are generally not recommended during pregnancy.
Breastfeeding Likely Unsafe When used orally ; avoid using. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Voxelotor and Alder Buckthorn? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Voxelotor

Interactions in our licensed database are recorded against drug classes, not just single drug names. Voxelotor is filed under 3 classifications — cytochrome p450 3a4 (cyp3a4) inhibitors, cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. Alder Buckthorn has documented interactions with 5 drug classes — the most serious being corticosteroids (moderate), digoxin (lanoxin) (moderate) and diuretic drugs (moderate) — and none of Voxelotor’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

Alder Buckthorn Does Interact With Other Medications

Alder Buckthorn has 122 moderate known drug interactions in our database — Voxelotor isn’t one of them. If you take anything else, check it against the full list below.

Moderate 122 No known interaction 2,708 (incl. Voxelotor)
Taking anything else?

Check Another of Your Medications Against Alder Buckthorn

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

What to actually watch for

What Alder Buckthorn Itself Has Been Linked To

This is not an interaction — nothing below involves Voxelotor. It is the side-effect record for Alder Buckthorn on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Alder Buckthorn, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • Low potassium Worth acting on Additional detail

    “Orally, alder buckthorn seems to be well tolerated when properly aged bark is used appropriately for no more than 8 to 10 days (12). Adverse effects include cramp-like discomfort (2). Chronic use, especially for 9 months or longer, is associated with damage to gastrointestinal epithelial cells and pigmentation of the colonic mucosa, known as pseudomelanosis coli.”

    Alder Buckthorn · Natural Medicines adverse-effect record, reported in albuminuria.

    6 sources cited
    1. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
    2. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    3. 30743. Siegers, C. P., Hertzberg-Lottin, E., Otte, M., and Schneider, B. Anthranoid laxative abuse--a risk for colorectal cancer? Gut 1993;34(8):1099-1101. PubMed
    4. 37266. van Gorkom, B. A., de Vries, E. G., Karrenbeld, A., and Kleibeuker, J. H. Review article: anthranoid laxatives and their potential carcinogenic effects. Aliment.Pharmacol Ther 1999;13(4):443-452. PubMed
    5. 37269. Willems, M., van Buuren, H. R., and de, Krijger R. Anthranoid self-medication causing rapid development of melanosis coli. Neth.J Med 2003;61(1):22-24.
    6. 6138. Nusko G, Schneider B, Schneider I, et al. Anthranoid laxative use is not a risk factor for colorectal neoplasia: results of a prospective case control study. Gut 2000;46:651-5. PubMed
  • Vomiting Additional detail

    “Orally, adverse effects include cramp-like discomfort (2). Chronic use, especially for 9 months or longer, is associated with damage to gastrointestinal epithelial cells and pigmentation of the colonic mucosa, known as pseudomelanosis coli. The fresh bark contains free anthrone, which can cause severe vomiting.”

    Alder Buckthorn · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    3 sources cited
    1. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    2. 30743. Siegers, C. P., Hertzberg-Lottin, E., Otte, M., and Schneider, B. Anthranoid laxative abuse--a risk for colorectal cancer? Gut 1993;34(8):1099-1101. PubMed
    3. 37266. van Gorkom, B. A., de Vries, E. G., Karrenbeld, A., and Kleibeuker, J. H. Review article: anthranoid laxatives and their potential carcinogenic effects. Aliment.Pharmacol Ther 1999;13(4):443-452. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Alder Buckthorn — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Voxelotor’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Voxelotor column appears here.

Special populations

Alder Buckthorn in Pregnancy & Breastfeeding

Lactation Likely Unsafe

When used orally ; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Voxelotor

This page covers Alder Buckthorn only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Voxelotor page lists 143 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 100 moderate · 40 minor.

From our pharmacist’s overview on the Voxelotor page

“Anyone taking voxelotor (Oxbryta) for sickle cell disease should treat this list with real care, because the pattern behind it is unusually consistent. Almost every entry works through CYP3A4, the same liver enzyme that clears voxelotor, so these ingredients can push the drug's blood level higher or pull it lower, either adding side ef…”

Reviewed by 2 · Jul 18, 2026

Open the Voxelotor interaction page

One more smart check

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

We hold 19 real supplement products containing Alder Buckthorn, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Alder Buckthorn. Even though Alder Buckthorn itself has no known interaction with Voxelotor, 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 Alder Buckthorn and Voxelotor 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 Alder Buckthorn
Top half

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

29 days ago today
Medication Voxelotor
Steady interest

#1,999 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 Alder Buckthorn reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Alder Buckthorn and Voxelotor records this page draws on were last updated July 11, 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 Alder Buckthorn

What is Alder Buckthorn?

Alder Buckthorn
  • Constipation
  • Bowel cleansing before procedures
  • Occasional irregularity

Alder buckthorn bark is a stimulant laxative traditionally used for short-term relief of constipation. It can work, but it carries real risks with prolonged use, including bowel damage, and should only be used briefly, if at all, after checking with a pharmacist or doctor.

Frangula alnus · Rhamnaceae · Dried, aged bark · Tea, dried bark, liquid extracts, capsules, tablets

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

Alder Buckthorn: dosing

There is no single official "correct" dose for alder buckthorn, and the strength of products can vary a lot. Do not exceed the labeled amount or use it for more than about a week without medical advice.

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

Read the full Alder Buckthorn monograph & all interactions
Medication

About Voxelotor

What Is Voxelotor Used For?

Brand name: Oxbryta

Oxbryta (voxelotor) is approved to treat sickle cell disease (SCD) in adults and in children as young as 4 years old. It works by targeting the underlying problem in sickle cell disease — the abnormal hemoglobin that causes red blood cells to take on a rigid, sickle shape.

This approval was granted under the FDA's accelerated approval pathway, based on the drug's ability to raise hemoglobin levels. Continued approval may depend on results from confirmatory clinical trials showing broader clinical benefit.

Most-Reported Side Effects for Voxelotor

From FAERS, the FDA’s public side-effect reporting system (22,300 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Sickle cell anaemia with crisis 11,218 reports
Diarrhea 3,187 reports
Nausea 2,016 reports
Headache 1,691 reports
Abdominal pain upper 1,171 reports
See full Voxelotor drug information
Keep checking

Other Drugs & Alder Buckthorn

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

0Major
122Moderate
0Minor
2,707No known interaction
122 Moderate 2,707 No interaction
Moderate

122 interactions

Showing 60 of 122 moderate interactions — see all 122 on the Alder Buckthorn page.

No interaction 2,707 drugs checked — show the list

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

Showing the 60 most looked-up of 2,707 medications checked with no known interaction — see the full Alder Buckthorn list.

See the full Alder Buckthorn interactions page
See every supplement checked against Voxelotor, ranked by severity
Evidence & sources

Alder Buckthorn References

The 10 references that drive our Alder Buckthorn 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. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Tyler VE. Herbs of Choice. Binghamton, NY: Pharmaceutical Products Press, 1994.
  3. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  4. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician's Guide to Herbal Medicine. Terry C. Telger, transl. 3rd ed. Berlin, GER: Springer, 1998.
  5. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  6. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  7. Nusko G, Schneider B, Schneider I, et al. Anthranoid laxative use is not a risk factor for colorectal neoplasia: results of a prospective case control study. Gut 2000;46:651-5. PubMed
  8. Siegers, C. P., Hertzberg-Lottin, E., Otte, M., and Schneider, B. Anthranoid laxative abuse--a risk for colorectal cancer? Gut 1993;34(8):1099-1101. PubMed
  9. van Gorkom, B. A., de Vries, E. G., Karrenbeld, A., and Kleibeuker, J. H. Review article: anthranoid laxatives and their potential carcinogenic effects. Aliment.Pharmacol Ther 1999;13(4):443-452. PubMed
  10. Willems, M., van Buuren, H. R., and de, Krijger R. Anthranoid self-medication causing rapid development of melanosis coli. Neth.J Med 2003;61(1):22-24.

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 Alder Buckthorn and Voxelotor Together: Common Questions

Is it safe to take Alder Buckthorn with Voxelotor?
We do not list a known interaction between Alder Buckthorn and Voxelotor. 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 Alder Buckthorn and Voxelotor combination checked?
Interactions in our licensed database are recorded against drug classes. Voxelotor is filed under 3 classifications, and Alder Buckthorn has documented interactions with 5 drug classes — none of Voxelotor'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 Alder Buckthorn interact with any other medications?
Yes. Alder Buckthorn has 122 documented drug interactions in our database — Voxelotor 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 Voxelotor interact with any supplements?
Yes. Voxelotor has documented interactions with 143 supplements in our database — Alder Buckthorn is not one of them. The Voxelotor 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

Alder Buckthorn monograph Uses, safety profile, and every drug interaction in one place Voxelotor drug information The full plain-English guide to this medication Voxelotor supplement interactions Every supplement checked against Voxelotor, 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 10 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Voxelotor and Alder Buckthorn?

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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.