Drug & supplement interaction

Acerola + Aspirin, Codeine Phosphate, Methocarbamol

Aspirin, Codeine Phosphate, Methocarbamol brand name: Robaxisal C.

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

Acerola has a minor interaction with Aspirin, Codeine Phosphate, Methocarbamol. Theoretically, acerola might reduce the clearance of aspirin; however, its vitamin C content is likely too low to produce clinically significant effects.

Read the full interaction report
SeverityMinor
LikelihoodUnlikely
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Acerola and Aspirin, Codeine Phosphate, Methocarbamol

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

Minor

ASPIRIN

Theoretically, acerola might reduce the clearance of aspirin; however, its vitamin C content is likely too low to produce clinically significant effects.
Acerola contains vitamin C. It has been suggested that acidification of the urine by vitamin C can decrease the urinary excretion of salicylates, increasing plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion. The vitamin C content of acerola is typically about 2000 mg per 100 grams. Thus, a clinically significant interaction between acerola and aspirin is unlikely.
Severity Minor Likelihood Unlikely Evidence B

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Good news here: the worry with acerola and your Robaxisal C tablet is mostly theoretical. Acerola is packed with vitamin C, and the idea is that vitamin C could make your urine more acidic, which in turn might slow how your kidneys flush out the aspirin (salicylate) part of this combination. In theory that could let aspirin build up a little, nudging up side effects like stomach upset or ringing in the ears.

In practice, though, studies show that even fairly large vitamin C doses don't really change urine pH or how aspirin is cleared. So a meaningful problem from acerola is unlikely. The codeine and methocarbamol pieces aren't part of this interaction. Still, if you take Robaxisal C regularly or want to use concentrated acerola supplements, it's worth a quick check with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  2. Mc Leod DC, Nahata MC. Inefficacy of ascorbic acid as a urinary acidifier (letter). N Engl J Med 1977;296:1413. DOI
  3. Hansten PD, Hayton WL. Effect of antacid and ascorbic acid on serum salicylate concentration. J Clin Pharmacol 1980;20:326-31. 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

Acerola Also Interacts With Other Medications

Acerola has 39 moderate, 88 minor known drug interactions in our database — the Aspirin, Codeine Phosphate, Methocarbamol one above is one of them. If you take anything else, check it against the full list below.

Moderate 39 Minor 88 No known interaction 2,703 (incl. Aspirin, Codeine Phosphate, Methocarbamol)
Taking anything else?

Check Another of Your Medications Against Acerola

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

Everything else you take

See Every Supplement That Interacts With Aspirin, Codeine Phosphate, Methocarbamol

This page covers Acerola only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Codeine Phosphate, Methocarbamol page lists 328 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Asarabacca (major), Beer (major) and Danshen (major).

By severity: 12 major · 282 moderate · 34 minor.

From our pharmacist’s overview on the Aspirin, Codeine Phosphate, Methocarbamol page

“Alcohol is the single riskiest thing to combine with Robaxisal C (aspirin, codeine phosphate, and methocarbamol). Beer and wine both carry major ratings backed by solid human evidence, because codeine and methocarbamol already slow breathing and reflexes, and alcohol deepens that sedation.”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin, Codeine Phosphate, Methocarbamol interaction page

One more smart check

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

We hold 2,642 real supplement products containing Acerola, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Acerola. Your product may carry other ingredients that interact with Aspirin, Codeine Phosphate, Methocarbamol too, on top of Acerola — 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 Acerola and Aspirin, Codeine Phosphate, Methocarbamol 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 Acerola
Top 10%

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

29 days ago today
Medication Aspirin, Codeine Phosphate, Methocarbamol
Top 25%

#572 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 Acerola

What is Acerola?

Acerola
  • Vitamin C source
  • Immune support
  • Antioxidant support
  • General wellness
  • Skin health

Acerola is a small tropical fruit prized for its very high natural vitamin C content, and it is mostly used as a food-based source of vitamin C and antioxidants. While vitamin C itself has well-known roles in the body, strong human studies showing that acerola specifically treats or prevents disease are limited. It is generally considered safe in food amounts, but check with your pharmacist or doctor before using concentrated supplements.

Read the full Acerola monograph & all interactions
Keep checking

Other Drugs & Acerola

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

0Major
39Moderate
88Minor
2,702No known interaction
39 Moderate 88 Minor 2,702 No interaction
Moderate

39 interactions

Minor

88 interactions

Showing 60 of 88 minor interactions — see all 88 on the Acerola page.

No interaction 2,702 drugs checked — show the list

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

Showing the 60 most looked-up of 2,702 medications checked with no known interaction — see the full Acerola list.

See the full Acerola interactions page
See every supplement checked against Aspirin, Codeine Phosphate, Methocarbamol, 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
Acerola monograph › Uses, safety, and every drug interaction in one place Aspirin, Codeine Phosphate, Methocarbamol supplement interactions › Every supplement checked against Aspirin, Codeine Phosphate, Methocarbamol, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Acerola and Aspirin, Codeine Phosphate, Methocarbamol Together: Common Questions

Can you take Acerola with Aspirin, Codeine Phosphate, Methocarbamol?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Acerola and Aspirin, Codeine Phosphate, Methocarbamol interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Aspirin, Codeine Phosphate, Methocarbamol and Acerola?

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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.