Drug & supplement interaction

Octacosanol + Carbidopa

Carbidopa brand name: Lodosyn.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Octacosanol has a moderate interaction with Carbidopa. Concomitant use may worsen symptoms of Parkinson disease.

Read the full interaction report
SeverityModerate
LikelihoodProbable
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Octacosanol and Carbidopa

Here is the interaction we found between these two, with the evidence behind it.

Moderate

LEVODOPA/CARBIDOPA (Sinemet)

Concomitant use may worsen symptoms of Parkinson disease.
One small clinical study suggests that octacosanol might worsen dyskinesias and increase nervous tension in some patients being treated with levodopa/carbidopa.
Severity Moderate Likelihood Probable Evidence D

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Carbidopa is almost always paired with levodopa (as in Sinemet) to help treat Parkinson's disease. Carbidopa itself doesn't ease symptoms; it protects levodopa so more of it reaches your brain. The concern with octacosanol shows up on the levodopa side of that combination.

A small study hinted that octacosanol might worsen dyskinesias (those extra, uncontrolled movements some people get on levodopa) and leave some folks feeling more jittery or tense. This is a theoretical interaction based mostly on limited human data, so it's not a sure thing, but Parkinson's medicine is finely tuned and small shifts can matter. Please don't change anything on your own. Check with your pharmacist or doctor before adding octacosanol.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Snider S. Octacosanol in parkinsonism. Ann Neurol 1984;16:723. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Octacosanol Also Interacts With Other Medications

Octacosanol has 247 moderate known drug interactions in our database — the Carbidopa one above is one of them. If you take anything else, check it against the full list below.

Moderate 247 No known interaction 2,583 (incl. Carbidopa)
Taking anything else?

Check Another of Your Medications Against Octacosanol

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

Everything else you take

See Every Supplement That Interacts With Carbidopa

This page covers Octacosanol 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 Octacosanol as Part of a Dietary Supplement Product? Check It for Interactions

We hold 435 real supplement products containing Octacosanol, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Octacosanol. Your product may carry other ingredients that interact with Carbidopa too, on top of Octacosanol — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Octacosanol 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 Octacosanol
Steady interest

#1,061 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Carbidopa
Steady interest

#1,429 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.

Supplement

About Octacosanol

What is Octacosanol?

Octacosanol
  • Physical performance and endurance
  • Cholesterol support
  • Parkinson's and movement concerns
  • Antioxidant support
  • General energy and stamina

Octacosanol is a waxy long-chain alcohol from plant sources that is most often promoted for exercise endurance and cholesterol support, but solid human evidence is limited and results are mixed. It appears generally well tolerated in supplement amounts, but it is not a proven treatment for any condition, so talk with your pharmacist or doctor before using it.

Read the full Octacosanol 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.

See full Carbidopa drug information
Keep checking

Other Drugs & Octacosanol

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

0Major
247Moderate
0Minor
2,582No known interaction
247 Moderate 2,582 No interaction
Moderate

247 interactions

Showing 60 of 247 moderate interactions — see all 247 on the Octacosanol page.

No interaction 2,582 drugs checked — show the list

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

Showing the 60 most looked-up of 2,582 medications checked with no known interaction — see the full Octacosanol list.

See the full Octacosanol interactions page
See every supplement checked against Carbidopa, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Octacosanol monograph › Uses, safety, and every drug interaction in one place Carbidopa supplement interactions › Every supplement checked against Carbidopa, ranked by severity Carbidopa drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Octacosanol and Carbidopa Together: Common Questions

Can you take Octacosanol with Carbidopa?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Octacosanol and Carbidopa interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Carbidopa and Octacosanol?

Our pharmacists answer your medication & supplement questions — free.

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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.