Drug & supplement interaction

Agmatine + Carbidopa

Carbidopa brand name: Lodosyn.

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 Agmatine and Carbidopa 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

Agmatine and Carbidopa

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 Carbidopa and Agmatine 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.

Agmatine safety at a glance

Agmatine overall Use caution Short-term use appears generally well tolerated, but long-term safety in humans is not well studied.
Pregnancy Avoid There is not enough safety data, so it is best to avoid use during pregnancy.
Breastfeeding Avoid There is not enough safety data, so it is best to avoid use while breastfeeding.

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

Still wondering about combining Carbidopa and Agmatine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Carbidopa

Interactions in our licensed database are recorded against drug classes, not just single drug names. Carbidopa is filed under 3 classifications — including oral drugs. Agmatine has documented interactions with 2 drug classes — the most serious being antidiabetes drugs (moderate) and antihypertensive drugs (moderate) — and none of Carbidopa’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

Agmatine Does Interact With Other Medications

Agmatine has 258 moderate known drug interactions in our database — Carbidopa isn’t one of them. If you take anything else, check it against the full list below.

Moderate 258 No known interaction 2,572 (incl. Carbidopa)
Taking anything else?

Check Another of Your Medications Against Agmatine

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

What to actually watch for

No Interaction Found — But Data Suggests Agmatine and Carbidopa 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.

  • Stomach upset / Diarrhea / Nausea Additional detail

    Agmatine

    “Orally, agmatine has been reported to cause diarrhea, dyspepsia, and nausea in two small clinical studies. Mild-to-moderate diarrhea and nausea were reported in 3 out of 24 patients taking agmatine sulfate 3.56 grams daily. These adverse effects appeared within 2-3 days of therapy and resolved upon treatment discontinuation.”

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

    2 sources cited
    1. 94736. Keynan O, Mirovsky Y, Dekel S, Gilad VH, Gilad GM. Safety and efficacy of dietary agmatine sulfate in lumbar disc-associated radiculopathy. An open-label, dose-escalating study followed by a randomized, double-blind, placebo-controlled trial. Pain Med 201 PubMed
    2. 94742. Shopsin B. The clinical antidepressant effect of exogenous agmatine is not reversed by parachlorophenylalanine: a pilot study. Acta Neuropsychiatr 2013;25(2):113-8. PubMed

    Carbidopa

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

Effects for Carbidopa come from the ADVERSE REACTIONS section of its FDA label; effects for Agmatine come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 52,609 voluntary FDA FAERS reports for Carbidopa 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.

Everything else you take

See Every Supplement That Interacts With Carbidopa

This page covers Agmatine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Carbidopa page lists 21 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Magnesium (major), 5-htp (moderate), Coffee Charcoal (moderate) and European Mandrake (moderate).

By severity: 2 major · 10 moderate · 9 minor.

From our pharmacist’s overview on the Carbidopa page

“Carbidopa (Lodosyn) keeps levodopa working in Parkinson's disease, so anything that blocks its absorption can cost real motor control, and two of the 21 supplements on this list do exactly that at a level rated major. Magnesium is the one that surprises people: in a human study it cut carbidopa absorption by 81 percent and levodopa's b…”

Reviewed by 2 · Jul 18, 2026

Open the Carbidopa interaction page

One more smart check

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

We hold 1,058 real supplement products containing Agmatine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Agmatine. Even though Agmatine itself has no known interaction with Carbidopa, 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 Agmatine and Carbidopa 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 Agmatine
Top 25%

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

29 days ago today
Medication Carbidopa
Top half

#789 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 Agmatine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Agmatine and Carbidopa 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 Agmatine

What is Agmatine?

Agmatine
  • Pre- and post-workout support
  • Muscle pumps and exercise performance
  • Cognitive support and mood
  • Nerve pain
  • General well-being

Agmatine is a compound your body makes from the amino acid arginine, and it is sold mainly as a workout and 'pump' supplement. Human evidence for most of its claimed benefits is limited and preliminary, so its true effects are uncertain. If you want to try it, talk with your pharmacist or doctor first, especially if you have health conditions or take other medicines.

Not a plant part; a compound made from the amino acid arginine · Capsules, tablets, bulk powder (usually as agmatine sulfate)

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

Agmatine: dosing

There is no officially established or standardized dose for agmatine. Doses used in supplements and small studies vary, and there is not enough evidence to recommend a single best amount.The safest approach is to follow the directions on the product label and start with the lowest suggested amount. Do not assume that taking more will work better or be safer.

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

Read the full Agmatine monograph & all interactions
Medication

About Carbidopa

What Is Carbidopa Used For?

Brand name: Lodosyn

Carbidopa tablets — sold under the brand name Lodosyn and as generic carbidopa — are used together with levodopa or carbidopa-levodopa to manage symptoms of Parkinson's disease, postencephalitic parkinsonism, and symptomatic parkinsonism that can result from carbon monoxide or manganese poisoning. Carbidopa is never used alone; it always works as a partner to levodopa-based therapy.

Lodosyn is specifically used when a patient taking carbidopa-levodopa isn't getting enough daily carbidopa from that combination, or when a patient needs the two drugs individually titrated (adjusted) rather than taken as a fixed combination. Adding carbidopa helps reduce the nausea and vomiting that levodopa often causes and allows lower doses of levodopa to be used.

Most-Reported Side Effects for Carbidopa

From FAERS, the FDA’s public side-effect reporting system (52,609 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fall 4,954 reports
Hallucination 4,554 reports
Tremor 3,533 reports
Dyskinesia 3,174 reports
Dizziness 2,837 reports
See full Carbidopa drug information
Keep checking

Other Drugs & Agmatine

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

0Major
258Moderate
0Minor
2,571No known interaction
258 Moderate 2,571 No interaction
Moderate

258 interactions

Showing 60 of 258 moderate interactions — see all 258 on the Agmatine page.

No interaction 2,571 drugs checked — show the list

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

Showing the 60 most looked-up of 2,571 medications checked with no known interaction — see the full Agmatine list.

See the full Agmatine interactions page
See every supplement checked against Carbidopa, ranked by severity
Evidence & sources

Agmatine References

The 3 references that drive our Agmatine 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. Piletz JE, Aricioglu F, Cheng JT, et al. Agmatine: clinical applications after 100 years in translation. Drug Discov Today 2013;18(17-18):880-93. PubMed
  2. Keynan O, Mirovsky Y, Dekel S, Gilad VH, Gilad GM. Safety and efficacy of dietary agmatine sulfate in lumbar disc-associated radiculopathy. An open-label, dose-escalating study followed by a randomized, double-blind, placebo-controlled trial. Pain Med 201 PubMed
  3. Shopsin B. The clinical antidepressant effect of exogenous agmatine is not reversed by parachlorophenylalanine: a pilot study. Acta Neuropsychiatr 2013;25(2):113-8. 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 Agmatine and Carbidopa Together: Common Questions

Is it safe to take Agmatine with Carbidopa?
We do not list a known interaction between Agmatine and Carbidopa. 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 Agmatine and Carbidopa have any of the same side effects?
Yes — our sources link each of them separately to 3 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.
How was the Agmatine and Carbidopa combination checked?
Interactions in our licensed database are recorded against drug classes. Carbidopa is filed under 3 classifications, and Agmatine has documented interactions with 2 drug classes — none of Carbidopa'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 Agmatine interact with any other medications?
Yes. Agmatine has 258 documented drug interactions in our database — Carbidopa 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 Carbidopa interact with any supplements?
Yes. Carbidopa has documented interactions with 21 supplements in our database — Agmatine is not one of them. The Carbidopa 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

Agmatine monograph Uses, safety profile, and every drug interaction in one place Carbidopa drug information The full plain-English guide to this medication Carbidopa supplement interactions Every supplement checked against Carbidopa, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Carbidopa and Agmatine?

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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.