Drug & supplement interaction

Collagen Type I (native) + Efavirenz

Efavirenz brand name: Sustiva.

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 Collagen Type I (native) and Efavirenz 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 Efavirenz

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 Efavirenz 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 Efavirenz, 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 Efavirenz 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 Efavirenz. 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 Efavirenz’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Efavirenz column appears here.

Everything else you take

See Every Supplement That Interacts With Efavirenz

This page covers Collagen Type I (native) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Efavirenz page lists 159 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 · 117 moderate · 39 minor.

From our pharmacist’s overview on the Efavirenz page

“Efavirenz (Sustiva) is an HIV medicine, so an interaction that weakens it can cost more than a bad day; it can invite viral resistance. That makes this a list to treat with genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Efavirenz interaction page

How much people look this up

Where Collagen Type I (native) and Efavirenz 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

#1,255 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Efavirenz
Top half

#1,196 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 Efavirenz 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 Efavirenz

What Is Efavirenz Used For?

Brand name: Sustiva

Efavirenz is used to treat HIV-1 (human immunodeficiency virus type 1) infection. It is always used together with other antiretroviral medicines — never on its own.

It is approved for adults and for children who are at least 3 months old and weigh at least 3.5 kg (about 7.7 lbs). Both the capsule and tablet forms are approved for this use.

Most-Reported Side Effects for Efavirenz

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.

Virologic failure 960 reports
Drug resistance 742 reports
Viral mutation identified 676 reports
Pathogen resistance 641 reports
Foetal exposure during pregnancy 621 reports
See full Efavirenz 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
2,829 No interaction
No interaction 2,829 drugs checked — show the list

We also checked Collagen Type I (native) 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 Collagen Type I (native) list.

See the full Collagen Type I (native) interactions page
See every supplement checked against Efavirenz, ranked by severity
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 Efavirenz Together: Common Questions

Is it safe to take Collagen Type I (native) with Efavirenz?
We do not list a known interaction between Collagen Type I (native) and Efavirenz. 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 Efavirenz interact with any supplements?
Yes. Efavirenz has documented interactions with 159 supplements in our database — Collagen Type I (native) is not one of them. The Efavirenz 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

Collagen Type I (native) monograph Uses, safety profile, and every drug interaction in one place Efavirenz drug information The full plain-English guide to this medication Efavirenz supplement interactions Every supplement checked against Efavirenz, 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 Efavirenz 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.