Drug & supplement interaction

Sulfur + Doxylamine Succinate

Doxylamine Succinate brand name: Unisom.

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 Sulfur and Doxylamine Succinate 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Sulfur and Doxylamine Succinate

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 Doxylamine Succinate and Sulfur 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Sulfur at all — not against Doxylamine Succinate, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Sulfur safety at a glance

Sulfur overall Use caution Topical sulfur is generally well tolerated, but it can irritate skin and oral forms are less studied.
Pregnancy Possibly Safe When applied topically and appropriately, short-term. Topical products containing sulfur in concentrations up to 6% have been safely applied nightly for up to 6... Read the full pregnancy detail
Breastfeeding Possibly Safe When applied topically and appropriately, short-term. Topical products containing sulfur in concentrations up to 6% have been safely applied nightly for up to 6... 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 Doxylamine Succinate and Sulfur? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Sulfur and Doxylamine Succinate May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Diarrhea Additional detail

    Sulfur

    “Topically, sulfur is generally well tolerated when used in concentrations of up to 10%. Adverse effects include skin dryness, irritation, and pruritus. Orally, sulfur has been reported to cause diarrhea and metabolic acidosis.”

    Sulfur · Natural Medicines adverse-effect record, reported in diarrhea.

    6 sources cited
    1. 27846. Roos, T. C., Alam, M., Roos, S., Merk, H. F., and Bickers, D. R. Pharmacotherapy of ectoparasitic infections. Drugs 2001;61(8):1067-88. PubMed
    2. 88112. Pelle, M. T., Crawford, G. H., and James, W. D. Rosacea: II. Therapy. J Am Acad Dermatol 2004;51:499-512.
    3. 88120. Gupta, A. K. and Nicol, K. The use of sulfur in dermatology. J Drugs Dermatol 2004;3(4):427-31.
    4. 88121. Akhavan, A. and Bershad, S. Topical acne drugs: review of clinical properties, systemic exposure, and safety. Am J Clin Dermatol 2003;4(7):473-92.
    5. 88126. Lin, A. N., Reimer, R. J., and Carter, D. M. Sulfur revisited. J Am Acad Dermatol 1988;18(3):553-8.
    6. 27845. Blum, J. E. and Coe, F. L. Metabolic acidosis after sulfur ingestion. N Engl J Med 1977;297(16):869-70. PubMed

    “Orally, sulfur is converted to sulfide in the gastrointestinal tract, causing intestinal irritation which can lead to diarrhea.”

    Sulfur · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 27845. Blum, J. E. and Coe, F. L. Metabolic acidosis after sulfur ingestion. N Engl J Med 1977;297(16):869-70. PubMed

    Doxylamine Succinate

    Listed in the ADVERSE REACTIONS section of the FDA label for Doxylamine Succinate. Read the label on DailyMed ›

Reported for Sulfur but not commonly for Doxylamine Succinate: kidney problems, dry skin and itching.

Effects for Doxylamine Succinate come from the ADVERSE REACTIONS section of its FDA label; effects for Sulfur come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 7,687 voluntary FDA FAERS reports for Doxylamine Succinate that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Sulfur in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Safe

When applied topically and appropriately, short-term. Topical products containing sulfur in concentrations up to 6% have been safely applied nightly for up to 6 nights. There is insufficient reliable information available about the safety of sulfur 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

Overlapping uses

What Doxylamine Succinate Is Prescribed For, and What Sulfur Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Doxylamine Succinate is a prescription medicine with approved uses on its FDA label. Sulfur is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Doxylamine Succinate is prescribed for: Diphenhydramine temporarily relieves symptoms of hay fever, other upper respiratory allergies, and the common cold — including runny nose, sneezing, itchy or watery eyes, and itching of the nose or throat. After Bite Xtra gel is formulated for topical use and is approved to temporarily relieve pain and itching from minor burns, minor cuts and scrapes, insect bites, minor skin irritations, and rashes from poison ivy, poison oak, and poison sumac.

Sulfur has been studied for:

  • Common cold studied, not established Sulfur has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Sulfur for common cold

    A preliminary clinical study suggests that taking a homeopathic product containing sulfur and German ipecac (Engystol, Heel GmbH) orally for up to 2 weeks during a cold provides similar symptomatic relief to conventional over-the-counter remedies such as antihistamines, antitussives, and NSAIDs.

    1 source cited
    1. 27849. Schmiedel, V. and Klein, P. A complex homeopathic preparation for the symptomatic treatment of upper respiratory infections associated with the common cold: An observational study. Explore (NY) 2006;2(2):109-14. PubMed

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Doxylamine Succinate on your own; if you are taking Sulfur for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Sulfur or Doxylamine Succinate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Sulfur or Doxylamine Succinate, 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 Doxylamine Succinate

This page covers Sulfur only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Doxylamine Succinate page lists 52 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), Angel's Trumpet (moderate) and Bacopa (moderate).

By severity: 3 major · 38 moderate · 11 minor.

From our pharmacist’s overview on the Doxylamine Succinate page

“Someone reaching for doxylamine succinate (Unisom) to fall asleep is often the same person browsing the supplement aisle, and that pairing deserves genuine care here. Doxylamine is a strongly anticholinergic antihistamine, meaning it dries you out, fogs thinking, and slows digestion, and 30 of the 52 flagged ingredients pile more of th…”

Reviewed by 2 · Jul 18, 2026

Open the Doxylamine Succinate interaction page

One more smart check

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

We hold 492 real supplement products containing Sulfur, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Sulfur. Even though Sulfur itself has no known interaction with Doxylamine Succinate, 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 Sulfur and Doxylamine Succinate 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 Sulfur
Top half

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

29 days ago today
Medication Doxylamine Succinate
Steady interest

#1,821 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 Sulfur reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Sulfur and Doxylamine Succinate records this page draws on were last updated July 10, 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 Sulfur

What is Sulfur?

  • Acne and oily skin
  • Rosacea
  • Seborrheic dermatitis and dandruff
  • Scabies and other skin parasites
  • Joint pain (as MSM)

Sulfur is a mineral used mainly in topical skin products for acne, rosacea, dandruff, and certain skin infections, and has a long history in dermatology. Topical sulfur is generally well tolerated but can be drying and smelly; oral sulfur supplements like MSM are taken for joint pain, though the evidence is limited. Talk with your pharmacist or doctor before starting any sulfur product.

Elemental sulfur (mineral) or sulfur-containing compounds · Topical creams, ointments, lotions, soaps, and bath products; oral MSM (methylsulfonylmethane) capsules and powders

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

Sulfur: dosing

There is no single standardized dose for sulfur, and the right amount depends on the product and how it is used. Topical products contain different concentrations of sulfur, so always follow the directions on the label.For oral supplements like MSM, there is no firmly established dose.

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

Read the full Sulfur monograph & all interactions
Medication

About Diphenhydramine

What Is Diphenhydramine Used For?

Brand name: Unisom

Diphenhydramine temporarily relieves symptoms of hay fever, other upper respiratory allergies, and the common cold — including runny nose, sneezing, itchy or watery eyes, and itching of the nose or throat.

After Bite Xtra gel is formulated for topical use and is approved to temporarily relieve pain and itching from minor burns, minor cuts and scrapes, insect bites, minor skin irritations, and rashes from poison ivy, poison oak, and poison sumac.

Most-Reported Side Effects for Doxylamine Succinate

From FAERS, the FDA’s public side-effect reporting system (7,687 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Somnolence 569 reports
Fatigue 421 reports
Nausea 363 reports
Dizziness 291 reports
Insomnia 281 reports
See full Diphenhydramine drug information
Keep checking

Other Drugs & Sulfur

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Sulfur list.

See the full Sulfur interactions page
See every supplement checked against Doxylamine Succinate, ranked by severity
Evidence & sources

Sulfur References

The 17 references that drive our Sulfur 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. Blum, J. E. and Coe, F. L. Metabolic acidosis after sulfur ingestion. N Engl J Med 1977;297(16):869-70. PubMed
  2. Roos, T. C., Alam, M., Roos, S., Merk, H. F., and Bickers, D. R. Pharmacotherapy of ectoparasitic infections. Drugs 2001;61(8):1067-88. PubMed
  3. Diaz, M., Cazorla, D., and Acosta, M. [Efficacy, safety and acceptability of precipitated sulphur petrolatum for topical treatment of scabies at the city of Coro, Falcon State, Venezuela]. Rev Invest Clin 2004;56(5):615-22.
  4. Schmiedel, V. and Klein, P. A complex homeopathic preparation for the symptomatic treatment of upper respiratory infections associated with the common cold: An observational study. Explore (NY) 2006;2(2):109-14. PubMed
  5. Weiser, M., Gegenheimer, L. H., and Klein, P. A randomized equivalence trial comparing the efficacy and safety of Luffa comp.-Heel nasal spray with cromolyn sodium spray in the treatment of seasonal allergic rhinitis. Forsch Komplementarmed 1999;6(3):142- PubMed
  6. FDA OTC ingredients list, April 2010. Available at: www.fda.gov/downloads/AboutFDA/CentersOffices/CDER/UCM135691.pdf (accessed 2/7/15).
  7. Leyden, J. J., McGinley, K. J., Mills, O. H., Kyriakopoulos, A. A., and Kligman, A. M. Effects of sulfur and salicylic acid in a shampoo base in the treatment of dandruff: a double-blind study using corneocyte counts and clinical grading. Cutis 1987;39(6)
  8. Trumbore, M. W., Goldstein, J. A., and Gurge, R. M. Treatment of papulopustular rosacea with sodium sulfacetamide 10%/sulfur 5% emollient foam. J Drugs Dermatol 2009;8(3):299-304.
  9. Pelle, M. T., Crawford, G. H., and James, W. D. Rosacea: II. Therapy. J Am Acad Dermatol 2004;51:499-512.
  10. Blom I, Hornmark AM. Topical treatment with sulfur 10 per cent for rosacea. Acta Derm Venereol 1984;64:358-9. DOI
  11. Gupta, A. K. and Nicol, K. The use of sulfur in dermatology. J Drugs Dermatol 2004;3(4):427-31.
  12. Akhavan, A. and Bershad, S. Topical acne drugs: review of clinical properties, systemic exposure, and safety. Am J Clin Dermatol 2003;4(7):473-92.
  13. Wilkinson RD, Adam JE, Murray JJ, Craig GE. Benzoyl peroxide and sulfur: foundation for acne management. Can Med Assoc J 1966;95(1):28-9.
  14. Food and Drug Administration. Classification of benzoyl peroxide as safe and effective and revision of labeling to drug facts format; topical acne drug products for over-the-counter human use; final rule. Federal Register 2010;75(42):9767-77.
  15. Lin, A. N., Reimer, R. J., and Carter, D. M. Sulfur revisited. J Am Acad Dermatol 1988;18(3):553-8.

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 Sulfur and Doxylamine Succinate Together: Common Questions

Is it safe to take Sulfur with Doxylamine Succinate?
We do not list a known interaction between Sulfur and Doxylamine Succinate. 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.
Do Sulfur and Doxylamine Succinate have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Sulfur and Doxylamine Succinate used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Sulfur in each. That is a conversation for your prescriber, especially if Doxylamine Succinate is being adjusted to a target.
Does Doxylamine Succinate interact with any supplements?
Yes. Doxylamine Succinate has documented interactions with 52 supplements in our database — Sulfur is not one of them. The Doxylamine Succinate 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

Sulfur monograph Uses, safety profile, and every drug interaction in one place Diphenhydramine drug information The full plain-English guide to this medication Doxylamine Succinate supplement interactions Every supplement checked against Doxylamine Succinate, 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 17 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Doxylamine Succinate and Sulfur?

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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.