Drug & supplement interaction

Acetyl-l-carnitine + Colestipol

Colestipol brand name: Colestid.

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 Acetyl-l-carnitine and Colestipol 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 label for Colestipol states a food rule worth keeping to, and 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

Acetyl-l-carnitine and Colestipol

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 Colestipol and Acetyl-l-carnitine 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.

Acetyl-l-carnitine safety at a glance

Acetyl-l-carnitine overall Use caution Generally well tolerated short-term, but long-term safety is not fully established.
Pregnancy Avoid There is not enough reliable safety information, so it is best avoided unless your doctor advises otherwise.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoiding it is the safer choice.

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

Still wondering about combining Colestipol and Acetyl-l-carnitine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Colestipol

Interactions in our licensed database are recorded against drug classes, not just single drug names. Colestipol is filed under 2 classifications — bile acid sequestrants, oral drugs. Acetyl-l-carnitine has documented interactions with 4 drug classes — the most serious being acenocoumarol (sintrom) (moderate), serotonergic drugs (moderate) and thyroid hormone (moderate) — and none of Colestipol’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

Acetyl-l-carnitine Does Interact With Other Medications

Acetyl-l-carnitine has 203 moderate known drug interactions in our database — Colestipol isn’t one of them. If you take anything else, check it against the full list below.

Moderate 203 No known interaction 2,627 (incl. Colestipol)
Taking anything else?

Check Another of Your Medications Against Acetyl-l-carnitine

Covers the 2,830 medications we’ve checked against Acetyl-l-carnitine. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Acetyl-l-carnitine and Colestipol May Share Several of the Same Side Effects

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.

  • Bloating or gas / Stomach upset / Constipation / Diarrhea / Vomiting / Nausea Additional detail

    Acetyl-l-carnitine

    “Orally, acetyl-L-carnitine may cause nausea, vomiting, diarrhea, constipation, hiccups, abdominal distension and gastrointestinal upset or pain. However, gastrointestinal symptoms do not usually occur more often in patients receiving acetyl-L-carnitine than in patients receiving placebo. Acetyl-L-carnitine may also cause dry mouth and anorexia.”

    Acetyl-l-carnitine · Natural Medicines adverse-effect record, reported in anorexia.

    2 sources cited
    1. 58342. Youle, M. and Osio, M. A double-blind, parallel-group, placebo-controlled, multicentre study of acetyl L-carnitine in the symptomatic treatment of antiretroviral toxic neuropathy in patients with HIV-1 infection. HIV.Med. 2007;8(4):241-250.
    2. 90441. Brennan BP, Jensen JE, Hudson JI, Coit CE, Beaulieu A, Pope HG Jr, Renshaw PF, Cohen BM. A placebo-controlled trial of acetyl-L-carnitine and a-lipoic acid in the treatment of bipolar depression. J Clin Psychopharmacol. 2013 Oct;33(5):627-35.

    Colestipol

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

  • Reduced appetite Additional detail

    Acetyl-l-carnitine

    “Orally, acetyl-L-carnitine is generally well tolerated.

    Most Common Adverse Effects:

    Orally: Agitation, dry mouth, headache, insomnia, and reduced appetite. A metabolite of acetyl-L-carnitine has been reported to cause a fishy odor of the urine, breath, and sweat.”

    Acetyl-l-carnitine · Natural Medicines adverse-effect record, reported in cluster headache.

    Colestipol

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

  • Trouble sleeping / Headache Additional detail

    Acetyl-l-carnitine

    “Orally, acetyl-L-carnitine may cause headache and insomnia. In one clinical trial, two patients with antiretroviral toxic neuropathy reported paresthesia, pain, and neuropathy after taking acetyl-L-carnitine 1000 mg daily. A case of mania has been reported for a patient with bipolar I disorder currently in remission.”

    Acetyl-l-carnitine · Natural Medicines adverse-effect record, reported in bipolar disorder.

    5 sources cited
    1. 90760. Ledinek AH, Sajko MC, Rot U. Evaluating the effects of amantadin, modafinil and acetyl-L-carnitine on fatigue in multiple sclerosis--result of a pilot randomized, blind study. Clin Neurol Neurosurg. 2013 Dec;115 Suppl 1:S86-9. PubMed
    2. 90767. Martinotti G, Andreoli S, Reina D, Di Nicola M, Ortolani I, Tedeschi D, Fanella F, Pozzi G, Iannoni E, D'Iddio S, Prof LJ. Acetyl-l-Carnitine in the treatment of anhedonia, melancholic and negative symptoms in alcohol dependent subjects. Prog Neuropsychop PubMed
    3. 95063. Bruno A, Pandolfo G, Crucitti M, Lorusso S, Zoccali RA, Muscatello MR. Acetyl-L-Carnitine Augmentation of Clozapine in Partial-Responder Schizophrenia: A 12-Week, Open-Label Uncontrolled Preliminary Study. Clin Neuropharmacol. 2016;39(6):277-80. PubMed
    4. 58342. Youle, M. and Osio, M. A double-blind, parallel-group, placebo-controlled, multicentre study of acetyl L-carnitine in the symptomatic treatment of antiretroviral toxic neuropathy in patients with HIV-1 infection. HIV.Med. 2007;8(4):241-250.
    5. 95062. Goodison G, Overeem K, de Monte V, Siskind D. Mania associated with self-prescribed acetyl-l-carnitine in a man with bipolar I disorder. Australas Psychiatry. 2017;25(1):13-4.

    Colestipol

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

Reported for Acetyl-l-carnitine but not commonly for Colestipol: raised blood pressure, mania or an unusually elevated mood, anxiety or restlessness and mood changes or irritability.

Effects for Colestipol come from the ADVERSE REACTIONS section of its FDA label; effects for Acetyl-l-carnitine come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

How to take them

Some Colestipol Products Have a Food Rule — Acetyl-l-carnitine Should Not Break It

At least one FDA label for a product containing Colestipol says to take it on an empty stomach. Most supplements — Acetyl-l-carnitine included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Colestipol on its own and move Acetyl-l-carnitine to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Colestipol products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Patients should take other drugs at least one hour before or four hours after colestipol hydrochloride tablets to minimize possible interference with their absorption.

From the Dosage and Administration section of the FDA label we read for Colestipol — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

From our Q&A

Questions About Acetyl-l-carnitine or Colestipol

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Acetyl-l-carnitine or Colestipol, 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 Colestipol

This page covers Acetyl-l-carnitine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Colestipol page lists 18 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 8 moderate · 9 minor.

From our pharmacist’s overview on the Colestipol page

“Take colestipol (Colestid), a cholesterol drug that works by trapping bile acids in your gut, and nearly every one of the 18 supplement interactions on file comes down to absorption. Only one rates major, activated charcoal, and it belongs at the top of your reading.”

Reviewed by 2 · Jul 18, 2026

Open the Colestipol interaction page

One more smart check

Taking Acetyl-l-carnitine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 405 real supplement products containing Acetyl-l-carnitine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Acetyl-l-carnitine. Even though Acetyl-l-carnitine itself has no known interaction with Colestipol, 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 Acetyl-l-carnitine and Colestipol 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 Acetyl-l-carnitine
Top 10%

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

29 days ago today
Medication Colestipol
Top 25%

#484 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 Acetyl-l-carnitine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Acetyl-l-carnitine and Colestipol 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 Acetyl-l-carnitine

What is Acetyl-l-carnitine?

Acetyl-l-carnitine
  • Memory and cognitive support
  • Nerve pain (neuropathy)
  • Energy and fatigue
  • Age-related decline
  • Male fertility
  • Mood support

Acetyl-L-carnitine is a form of the amino acid carnitine that the body uses to help produce energy in cells. It is most studied for nerve pain and memory-related conditions, though the evidence is mixed and often limited. It is generally well tolerated for short-term use, but you should talk with your pharmacist or doctor before starting it.

Not applicable (a naturally occurring compound made in the body) · Capsules, tablets, powder, and liquid

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

Acetyl-l-carnitine: dosing

There is no single official dose of Acetyl-L-carnitine for any condition. Taking it with food may help reduce stomach upset. Do not assume that taking more will work better, as higher amounts can increase the chance of side effects.

From our Acetyl-l-carnitine monograph — the full record covers uses, side effects and every documented interaction.

Read the full Acetyl-l-carnitine monograph & all interactions
Medication

About Colestipol

What Is Colestipol Used For?

Brand name: Colestid

Colestipol — available as oral suspension and tablets under brands including Colestid, Flavored Colestid, and Colestipol Hydrochloride — is used as part of a broader treatment plan (including diet) to lower elevated LDL cholesterol in adults with primary hypercholesterolemia (a condition where LDL cholesterol stays high despite dietary changes).

It is not a standalone fix. Diet, weight management, and other lifestyle changes come first, and colestipol is added when those steps alone aren't enough to reach target LDL levels.

See full Colestipol drug information
Keep checking

Other Drugs & Acetyl-l-carnitine

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

0Major
203Moderate
0Minor
2,626No known interaction
203 Moderate 2,626 No interaction
Moderate

203 interactions

Showing 60 of 203 moderate interactions — see all 203 on the Acetyl-l-carnitine page.

No interaction 2,626 drugs checked — show the list

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

Showing the 60 most looked-up of 2,626 medications checked with no known interaction — see the full Acetyl-l-carnitine list.

See the full Acetyl-l-carnitine interactions page
See every supplement checked against Colestipol, ranked by severity
Evidence & sources

Acetyl-l-carnitine References

The 22 references that drive our Acetyl-l-carnitine 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. Thal LJ, Carta A, Clarke WR, et al. A 1-year multicenter placebo-controlled study of acetyl-L-carnitine in patients with Alzheimer's Disease. Neurology 1996;47:705-11. PubMed
  2. Sano M, Bell K, Cote L, et al. Double-blind parallel design pilot study of acetyl levocarnitine in patients with Alzheimer's Disease. Arch Neurol 1992;49:1137-41. PubMed
  3. Spagnoli A, Lucca U, Menasce G, et al. Long-term acetyl-L-carnitine treatment in Alzheimer's Disease. Neurology 1991;41:1726-32. PubMed
  4. Brooks JO 3rd, Yesavage JA, Carta A, Bravi D. Acetyl L-carnitine slows decline in younger patients with Alzheimer's disease: a reanalysis of a double-blind, placebo-controlled study using the trilinear approach. Int Psychoger 1998;10:193-203. PubMed
  5. Pettegrew JW, Klunk WE, Panchalingam K, et al. Clinical and neurochemical effects of acetyl-L-carnitine in Alzheimer's disease. Neurobiol Aging 1995;16:1-4. PubMed
  6. Rai G, Wright G, Scott L, et al. Double-blind, placebo controlled study of acetyl-l-carnitine in patients with Alzheimer's dementia. Curr Med Res Opin 1990;11:638-47. PubMed
  7. Benvenga S, Ruggeri RM, Russo A, et al. Usefulness of L-carnitine, a naturally occurring peripheral antagonist of thyroid hormone action, in iatrogenic hyperthyroidism: a randomized, double-blind, placebo-controlled clinical trial. J Clin Endocrinol Meta
  8. Montgomery SA, Thal LJ, Amrein R. Meta-analysis of double blind randomized controlled clinical trials of acetyl-L-carnitine versus placebo in the treatment of mild cognitive impairment and mild Alzheimer's disease. Int Clin Psychopharmacol 2003;18:61-71.. PubMed
  9. Martinez E, Domingo P, Roca-Cusachs A. Potentiation of acenocoumarol action by L-carnitine. J Intern Med 1993;233:94.
  10. Hudson S, Tabet N. Acetyl-L-carnitine for dementia. Cochrane Database Syst Rev 2003;2:CD003158.. PubMed
  11. Bachmann HU, Hoffmann A. Interaction of food supplement L-carnitine with oral anticoagulant acenocoumarol. Swiss Med Wkly 2004;134:385. PubMed
  12. De Grandis D, Minardi C. Acetyl-L-carnitine (levacecarnine) in the treatment of diabetic neuropathy. A long-term, randomised, double-blind, placebo-controlled study. Drugs R D 2002;3:223-31. PubMed
  13. 12761 Benvenga S, Amato A, Calvani M, Trimarchi F. Effects of carnitine on thyroid hormone action. Ann N Y Acad Sci 2004;1033:158-67. PubMed
  14. Sima AAF, Calvani M, Mehra M, et al. Acetyl-L-carnitine improves pain, nerve regeneration, and vibratory perception in patients with chronic diabetic neuropathy: An analysis of two randomized, placebo-controlled trials. Diabetes Care 2005;28:89-94.
  15. Youle, M. and Osio, M. A double-blind, parallel-group, placebo-controlled, multicentre study of acetyl L-carnitine in the symptomatic treatment of antiretroviral toxic neuropathy in patients with HIV-1 infection. HIV.Med. 2007;8(4):241-250.

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 Acetyl-l-carnitine and Colestipol Together: Common Questions

Is it safe to take Acetyl-l-carnitine with Colestipol?
We do not list a known interaction between Acetyl-l-carnitine and Colestipol. 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 Acetyl-l-carnitine and Colestipol have any of the same side effects?
Yes — our sources link each of them separately to 9 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.
Should I take Acetyl-l-carnitine and Colestipol at the same time of day?
At least one FDA label for a product containing Colestipol says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Colestipol on its own and move Acetyl-l-carnitine to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
How was the Acetyl-l-carnitine and Colestipol combination checked?
Interactions in our licensed database are recorded against drug classes. Colestipol is filed under 2 classifications, and Acetyl-l-carnitine has documented interactions with 4 drug classes — none of Colestipol'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 Acetyl-l-carnitine interact with any other medications?
Yes. Acetyl-l-carnitine has 203 documented drug interactions in our database — Colestipol 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 Colestipol interact with any supplements?
Yes. Colestipol has documented interactions with 18 supplements in our database — Acetyl-l-carnitine is not one of them. The Colestipol 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

Acetyl-l-carnitine monograph Uses, safety profile, and every drug interaction in one place Colestipol drug information The full plain-English guide to this medication Colestipol supplement interactions Every supplement checked against Colestipol, 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 22 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

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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.