Drug & supplement interaction

L-carnitine + Insulin Lispro

Insulin Lispro brand names: Admelog, Admelog Solostar.

No Known Interaction
The bottom line No known interaction

We found no known interaction between L-carnitine and Insulin Lispro 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 Insulin Lispro 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.

Know someone taking this? Share
Interaction report

L-carnitine and Insulin Lispro

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 Insulin Lispro and 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.

L-carnitine safety at a glance

L-carnitine overall Use caution Generally well tolerated at typical doses, but high doses can cause stomach upset and a fishy body odor.
Pregnancy Use caution Not enough reliable safety data; use only under medical supervision.
Breastfeeding Possibly Safe When used orally. Supplemental doses of L-carnitine have been given to infants in breast milk and formula with no reported adverse effects. The effects of large... 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 Insulin Lispro and L-carnitine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Insulin Lispro

Interactions in our licensed database are recorded against drug classes, not just single drug names. Insulin Lispro is filed under a single classification — antidiabetes drugs. L-carnitine has documented interactions with 3 drug classes — the most serious being acenocoumarol (sintrom) (moderate), thyroid hormone (moderate) and warfarin (coumadin) (moderate) — and none of Insulin Lispro’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

L-carnitine Does Interact With Other Medications

L-carnitine has 19 moderate known drug interactions in our database — Insulin Lispro isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against L-carnitine

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

What to actually watch for

No Interaction Found — But Data Suggests L-carnitine and Insulin Lispro 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.

  • Itching / A skin rash Additional detail

    L-carnitine

    “Orally, L-carnitine has been reported to cause skin rash in a small number of cases.

    Two patients in a hair growth study using topical carnitine reported mild itching and increased dandruff, while a third reported strong itching with reddish bumps and a burning sensation.”

    L-carnitine · Natural Medicines adverse-effect record, reported in pruritus.

    4 sources cited
    1. 16105. Ciacci C, Peluso G, Iannoni E, et al. L-Carnitine in the treatment of fatigue in adult celiac disease patients: a pilot study. Dig Liver Dis 2007;39:922-8. PubMed
    2. 91724. Jun DW, Kim BI, Cho YK, Kim HJ, Kwon YO, Park SY, Han SY, Baek YH, Jung YJ, Kim HY, Kim W, Heo J, Woo HY, Hwang SG, Rim KS, Choi JY, Bae SH, Lee YS, Lim YS,Cheong JY, Cho SW, Lee BS, Kim SH, Sohn JH, Kim TY, Paik YH, Kim JK, Lee KS. Efficacy and safety of
    3. 58390. Foitzik, K., Hoting, E., Heinrich, U., Tronnier, H., and Paus, R. Indications that topical L-carnitin-L-tartrate promotes human hair growth in vivo. J Dermatol.Sci 2007;48(2):141-144. PubMed
    4. 26493. Angelova-Fischer I, Rippke F, Fischer TW, Neufang G, Zillikens D. A double-blind, randomized, vehicle-controlled efficacy assessment study of a skin care formulation for improvement of mild to moderately severe acne. J Eur Acad Dermatol Venereol. 2013 Jul PubMed

    Insulin Lispro

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

Reported for L-carnitine but not commonly for Insulin Lispro: stomach upset, a heart attack, stomach pain and reduced appetite.

Effects for Insulin Lispro come from the ADVERSE REACTIONS section of its FDA label; effects for 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.

Special populations

L-carnitine in Pregnancy & Breastfeeding

Lactation Possibly Safe

When used orally. Supplemental doses of L-carnitine have been given to infants in breast milk and formula with no reported adverse effects. The effects of large doses used while nursing are unknown, but L-carnitine is secreted in the breast milk.

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

How to take them

Some Insulin Lispro Products Have a Food Rule — L-carnitine Should Not Break It

At least one FDA label for a product containing Insulin Lispro says to take it with food. If you take L-carnitine on an empty stomach out of habit, keep them separate — and take Insulin Lispro with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Insulin Lispro 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.

( 2.1 , 2.2 , 2.3 , 2.4 ) Subcutaneous injection ( 2.2 ): Administer HUMALOG ® U-100 or U-200 by subcutaneous injection into the abdominal wall, thigh, upper arm, or buttocks within 15 minutes before a meal or immediately after a meal.

From the Dosage and Administration section of the FDA label we read for Insulin Lispro — 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.

Overlapping uses

What Insulin Lispro Is Prescribed For, and What L-carnitine Has Been Studied For

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

Insulin Lispro is prescribed for: Insulin lispro injection is used to improve glycemic control (blood sugar management) in people with diabetes mellitus. It is a rapid-acting insulin analog approved for use in both type 1 and type 2 diabetes. Admelog is specifically indicated to improve glycemic control in patients with diabetes mellitus. Humalog Mix75/25 is indicated to improve glycemic control in adults with diabetes mellitus; it is a fixed-ratio mixture of insulin lispro and insulin lispro protamine, and its fixed proportions do not allow for separate adjustment of basal (background) and prandial (mealtime) doses.

L-carnitine has been studied for:

  • Kidney failure Natural Medicines rates the evidence for L-carnitine: Possibly Effective Read what the research shows

    L-carnitine for kidney failure

    Intravenous, but not oral, L-carnitine is FDA-approved for the prevention and treatment of L-carnitine deficiency in patients with kidney failure undergoing hemodialysis. Any other benefits with the use of L-carnitine in patients on hemodialysis are unclear.

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 Insulin Lispro on your own; if you are taking L-carnitine for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About L-carnitine or Insulin Lispro

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

This page covers L-carnitine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Insulin Lispro page lists 239 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Siberian Cocklebur (major), Acai (moderate), African Wild Potato (moderate), Agaricus Mushroom (moderate) and Agmatine (moderate).

By severity: 1 major · 208 moderate · 30 minor.

From our pharmacist’s overview on the Insulin Lispro page

“Blood sugar is the entire subject of this list. Insulin lispro (Admelog) is a rapid mealtime insulin dosed to bring glucose down after eating, and the supplements below can shove that same number around, most of them downward, which risks a genuine low.”

Reviewed by 2 · Jul 18, 2026

Open the Insulin Lispro interaction page

One more smart check

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

We hold 3,350 real supplement products containing L-carnitine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides L-carnitine. Even though L-carnitine itself has no known interaction with Insulin Lispro, 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 L-carnitine and Insulin Lispro 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 L-carnitine
Top 10%

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

29 days ago today
Medication Insulin Lispro
Top half

#1,214 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 L-carnitine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The L-carnitine and Insulin Lispro 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 L-carnitine

What is L-carnitine?

  • Exercise performance and recovery
  • Heart health
  • Weight management
  • Energy and fatigue
  • Male fertility
  • Carnitine deficiency

L-carnitine is a compound your body makes naturally and also gets from foods like meat. It helps cells turn fat into energy, and supplements are most clearly useful for people with a true carnitine deficiency. For most other uses, like weight loss or boosting athletic performance, the evidence is mixed or limited, so talk with your pharmacist or doctor before trying it.

Capsules, tablets, oral liquid, powder, and injectable (prescription) forms

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

L-carnitine: dosing

There is no single standard dose of L-carnitine that fits everyone, and the right amount depends on the form and the reason for use. Prescription carnitine for true deficiency is dosed by a doctor based on medical needs.For over-the-counter supplements, the best approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full L-carnitine monograph & all interactions
Medication

About Insulin Lispro Injection

What Is Insulin Lispro Injection Used For?

Brand names: Admelog, Admelog Solostar

Insulin lispro injection is used to improve glycemic control (blood sugar management) in people with diabetes mellitus. It is a rapid-acting insulin analog approved for use in both type 1 and type 2 diabetes.

Admelog is specifically indicated to improve glycemic control in patients with diabetes mellitus. Humalog Mix75/25 is indicated to improve glycemic control in adults with diabetes mellitus; it is a fixed-ratio mixture of insulin lispro and insulin lispro protamine, and its fixed proportions do not allow for separate adjustment of basal (background) and prandial (mealtime) doses.

See full Insulin Lispro Injection drug information
Keep checking

Other Drugs & L-carnitine

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

0Major
19Moderate
0Minor
2,810No known interaction
Moderate

19 interactions

No interaction 2,810 drugs checked — show the list
Evidence & sources

L-carnitine References

The 41 references that drive our 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. Ellaway CM, Williams K, Leonard H, et al. Rett syndrome: randomized controlled trial of L-carnitine. J Child Neurol 1999;14:162-7. PubMed
  2. Anon. Carnitor (levocarnitine) package insert. Sigma-Tau Pharmaceuticals Inc, Gaithersburg, MD. December 1999.
  3. Cherchi A, Lai C, Angelino F, et al. Effects of L-carnitine on exercise tolerance in chronic stable angina: a multicenter, double-blind, randomized, placebo-controlled, crossover study. Int J Clin Pharmacol Ther Toxicol 1985;23:569-72.
  4. Plioplys AV, Plioplys S. Amantadine and L-carnitine treatment of Chronic Fatigue Syndrome. Neuropsychobiology 1997;35:16-23. PubMed
  5. 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
  6. Martinez E, Domingo P, Roca-Cusachs A. Potentiation of acenocoumarol action by L-carnitine. J Intern Med 1993;233:94.
  7. Bachmann HU, Hoffmann A. Interaction of food supplement L-carnitine with oral anticoagulant acenocoumarol. Swiss Med Wkly 2004;134:385. PubMed
  8. Evans AM, Fornasini G. Pharmacokinetics of L-carnitine. Clin Pharmacokinet 2003;42:941-67. PubMed
  9. 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
  10. Ciacci C, Peluso G, Iannoni E, et al. L-Carnitine in the treatment of fatigue in adult celiac disease patients: a pilot study. Dig Liver Dis 2007;39:922-8. PubMed
  11. Cruciani RA, Dvorkin E, Homel P, et al. Safety, tolerability and symptom outcomes associated with L-carnitine supplementation in patients with cancer, fatigue, and carnitine deficiency: a phase I/II study. J Pain Symptom Manage 2006;32:551-9. PubMed
  12. Lebrun C, Alchaar H, Candito M, et al. Levocarnitine administration in multiple sclerosis patients with immunosuppressive therapy-induced fatigue. Mult Scler 2006;12:321-4. PubMed
  13. Malaguarnera M, Cammalleri L, Gargante MP, et al. L-Carnitine treatment reduces severity of physical and mental fatigue and increases cognitive functions in centenarians: a randomized and controlled clinical trial. Am J Clin Nutr 2007;86:1738-44. PubMed
  14. Mantovani G, Maccio A, Madeddu C, et al. Randomized phase III clinical trial of five different arms of treatment in 322 patients with cancer cachexia. Oncologist 2010;15:200-11.
  15. Angelova-Fischer I, Rippke F, Fischer TW, Neufang G, Zillikens D. A double-blind, randomized, vehicle-controlled efficacy assessment study of a skin care formulation for improvement of mild to moderately severe acne. J Eur Acad Dermatol Venereol. 2013 Jul PubMed

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 L-carnitine and Insulin Lispro Together: Common Questions

Is it safe to take L-carnitine with Insulin Lispro?
We do not list a known interaction between L-carnitine and Insulin Lispro. 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 L-carnitine and Insulin Lispro have any of the same side effects?
Yes — our sources link each of them separately to 2 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 L-carnitine and Insulin Lispro at the same time of day?
At least one FDA label for a product containing Insulin Lispro says to take it with food. If you take L-carnitine on an empty stomach out of habit, keep them separate and take Insulin Lispro with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Insulin Lispro products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Are L-carnitine and Insulin Lispro 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 L-carnitine in each. That is a conversation for your prescriber, especially if Insulin Lispro is being adjusted to a target.
How was the L-carnitine and Insulin Lispro combination checked?
Interactions in our licensed database are recorded against drug classes. Insulin Lispro is filed under 1 classification, and L-carnitine has documented interactions with 3 drug classes — none of Insulin Lispro'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 L-carnitine interact with any other medications?
Yes. L-carnitine has 19 documented drug interactions in our database — Insulin Lispro 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 Insulin Lispro interact with any supplements?
Yes. Insulin Lispro has documented interactions with 239 supplements in our database — L-carnitine is not one of them. The Insulin Lispro 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 Insulin Lispro and L-carnitine?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.