Drug & supplement interaction

Collagen Type I (native) + Clemastine

Clemastine brand name: Tavist Allergy.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Collagen Type I (native) and Clemastine 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

Collagen Type I (native) and Clemastine

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 Clemastine and Collagen Type I (native) 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 Collagen Type I (native) at all — not against Clemastine, 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.

Collagen Type I (native) safety at a glance

Collagen Type I (n... overall Use caution Generally well tolerated for most adults, but quality and source vary widely between products.
Pregnancy Avoid Safety has not been established, so it is best to avoid unless your doctor approves.
Breastfeeding Avoid Not enough safety data exists, so avoid use while breastfeeding unless advised otherwise.

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

Still wondering about combining Clemastine and Collagen Type I (native)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Collagen Type I (native) Itself Has Been Linked To

This is not an interaction — nothing below involves Clemastine. It is the side-effect record for Collagen Type I (native) on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Collagen Type I (native), this list is the first place to look.

  • Stomach upset Additional detail

    “Orally, dyspepsia occurred in one patient in one clinical trial.”

    Collagen Type I (native) · Natural Medicines adverse-effect record, reported in dyspepsia.

    1 source cited
    1. 101769. Stancík R, Zvarka J, Hlavác M, Kubinec V, Rovenský J. Collagen type I in the treatment of painful osteoarthritis of the knee. Reumatologia. 2012;50(5):390-6. DOI

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

From our Q&A

Questions About Collagen Type I (native) or Clemastine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Collagen Type I (native) or Clemastine, 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 Clemastine

This page covers Collagen Type I (native) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Clemastine page lists 72 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), Alfalfa (moderate) and Angel's Trumpet (moderate).

By severity: 3 major · 57 moderate · 12 minor.

From our pharmacist’s overview on the Clemastine page

“Clemastine (Tavist Allergy) is an older, sedating antihistamine that already dries the mouth, blurs vision, and slows the gut, and that is exactly why this list earns real caution rather than a quick skim. Thirty of the 72 supplements on file pile the same drying, sedating anticholinergic load on top, and two of the three major-rated e…”

Reviewed by 2 · Jul 18, 2026

Open the Clemastine interaction page

How much people look this up

Where Collagen Type I (native) and Clemastine 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 Collagen Type I (native)
Steady interest

#1,256 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Clemastine
Steady interest

#2,002 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 Collagen Type I (native) reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Collagen Type I (native) and Clemastine 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 Collagen Type I (native)

What is Collagen Type I (native)?

  • Skin health and wrinkles
  • Joint comfort and arthritis
  • Bone strength
  • Hair and nail support
  • Wound and tissue repair

Type I collagen is the most abundant protein in human skin, bones, and tendons, and it is sold as a supplement to support skin, joints, and bones. 'Native' (undenatured) Type I collagen keeps its natural triple-helix structure rather than being broken down into peptides. Early research is promising for skin and joints, but evidence is still limited, and most products are generally well tolerated.

Skin, bones, tendons, scales, and connective tissue of cows, pigs, fish, or chicken · Powders, capsules, drinks, and undenatured (native) collagen tablets

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

Collagen Type I (native): dosing

There is no official standardized dose for native Type I collagen, and the right amount depends on the specific product. Doses used in studies vary widely depending on the form (powder versus tablet) and whether the collagen is native or hydrolyzed.The safest approach is to follow the directions on the product label and not exceed them.

From our Collagen Type I (native) monograph — the full record covers uses, side effects and every documented interaction.

Read the full Collagen Type I (native) monograph & all interactions
Medication

About Clemastine

What Is Clemastine Used For?

Brand name: Tavist Allergy

Clemastine treats symptoms of allergic rhinitis (hay fever and similar nasal allergies) — including sneezing, runny nose, itching, and watery eyes. The oral solution (Clemastine Fumarate syrup) is indicated for adults and children aged 6 through 12 years. The tablets (Clemastine Fumarate and Clemsza) are indicated for adults.

Clemastine also treats mild, uncomplicated allergic skin reactions — specifically urticaria (hives) and angioedema (swelling under the skin) — at the appropriate dosage level, in both the oral solution and tablet forms.

See full Clemastine drug information
Keep checking

Other Drugs & Collagen Type I (native)

Browse every other medication we’ve checked against Collagen Type I (native) — 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Collagen Type I (native) References

The 1 references that drive our Collagen Type I (native) 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. Stancík R, Zvarka J, Hlavác M, Kubinec V, Rovenský J. Collagen type I in the treatment of painful osteoarthritis of the knee. Reumatologia. 2012;50(5):390-6. DOI

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 Collagen Type I (native) and Clemastine Together: Common Questions

Is it safe to take Collagen Type I (native) with Clemastine?
We do not list a known interaction between Collagen Type I (native) and Clemastine. 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.
Does Clemastine interact with any supplements?
Yes. Clemastine has documented interactions with 72 supplements in our database — Collagen Type I (native) is not one of them. The Clemastine interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Clemastine and Collagen Type I (native)?

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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.