Drug & supplement interaction

Danshen + Aspirin, Caffeine, Dihydrocodeine Bitartrate

Aspirin, Caffeine, Dihydrocodeine Bitartrate brand name: Synalgos DC.

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

Aspirin, Caffeine, Dihydrocodeine Bitartrate falls into 4 drug categories that Danshen can interact with; the most serious is rated major. Theoretically, danshen may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.

Read the full interaction report
SeverityMajor
LikelihoodProbable
Interactions4
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Danshen and Aspirin, Caffeine, Dihydrocodeine Bitartrate

These two interact in 4 distinct ways. Each one is explained separately below.

Why Are There 4 Interactions?

Danshen interacts with whole categories of medication. Aspirin, Caffeine, Dihydrocodeine Bitartrate falls into 4 of those categories, so it can interact with Danshen in 4 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Major).

Major

ANTICOAGULANT/ANTIPLATELET DRUGS

1 of 4

Why this applies to Aspirin, Caffeine, Dihydrocodeine Bitartrate

Aspirin, Caffeine, Dihydrocodeine Bitartrate falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Danshen interacts with.

Theoretically, danshen may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Danshen has been reported to have antithrombotic effects. Animal research also suggests that taking a danshen combination formula with clopidogrel exhibits a synergistic increase in antiplatelet aggregation and prolongation of coagulation time when compared with either taken alone.
Severity Major 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

Here's the thing to watch with this combo: the aspirin part of Synalgos DC is a blood thinner. It keeps your platelets from clumping together, which is how aspirin can cause bruising and stomach bleeding even on its own. Danshen seems to work in a similar direction, gently slowing clotting and reducing platelet stickiness. Stack the two and you may bump up your bleeding risk a bit more than aspirin alone.

I want to be honest about the evidence though. This is mostly theoretical, based on animal studies and a few case reports, not strong human trials. So it's not a reason to panic, just a good reason to check with your pharmacist or doctor before pairing them, especially if you notice easy bruising, nosebleeds, or dark stools.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm 2000;57:1221-7. DOI
  2. Yin QS, Chen L, Mi RH, Ai H, Yin JJ, Liu XJ, Wei XD. Efficacy and safety of danshen compound tablets in preventing thalidomide-associated thromboembolism in patients with multiple myeloma: a multicenter retrospective study. Med Sci Monit. 2016 Oct 20;22:3 PubMed
  3. Zheng D, Zhang W, Hou M, et al. Evaluation of herb-drug interactions between compound Danshen dripping pills and clopidogrel based on the pharmacokinetics and pharmacodynamics in rats. Biomed Chromatogr. 2023;37(9):e5684. PubMed
Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 4

Aspirin, Caffeine, Dihydrocodeine Bitartrate also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, danshen may increase the levels and clinical effects of drugs metabolized by CYP1A2.
In vitro research shows that danshen tincture and various constituents of danshen inhibit the activity of CYP1A2. However, this activity has not been shown in humans when theophylline, a CYP1A2 substrate, was used as a target drug.
Severity Moderate Likelihood Possible Evidence D

Interaction 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.

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

Here's the piece of this combo pill that matters most for the Danshen question: the caffeine. Caffeine is cleared by a liver enzyme called CYP1A2. In test-tube studies, Danshen seems to slow that enzyme down, which could in theory let caffeine linger longer and pile up a bit. If that happened, you might feel more jittery, anxious, restless, or have trouble sleeping or a racing heartbeat.

I want to be honest about how shaky this evidence is. It comes only from lab work, and when researchers tested it in real people using a similar CYP1A2 drug, they didn't see the effect. So this is mostly theoretical. There's a separate, more practical concern worth mentioning: both Danshen and the aspirin in this product can thin the blood, which may raise bleeding risk. I'd run both of these by your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wang X, Cheung CM, Lee WY, Or PM, Yeung JH. Major tanshinones of Danshen (Salvia miltiorrhiza) exhibit different modes of inhibition on human CYP1A2, CYP2C9, CYP2E1 and CYP3A4 activities in vitro. Phytomedicine. 2010 Sep;17(11):868-75. PubMed
  2. Wang X, Yeung JH. Investigation of cytochrome P450 1A2 and 3A inhibitory properties of Danshen tincture. Phytomedicine. 2012 Feb 15;19(3-4):348-54. PubMed
  3. Zhou X, Chan K, Yeung JH. Herb-drug interactions with Danshen (Salvia miltiorrhiza): a review on the role of cytochrome P450 enzymes. Drug Metabol Drug Interact. 2012 Mar 2;27(1):9-18.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 4

Aspirin, Caffeine, Dihydrocodeine Bitartrate also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Danshen might alter the levels and clinical effects of drugs metabolized by CYP3A4.
Preliminary clinical research in healthy males shows that the administration of danshen for 10-14 days induces intestinal CYP3A4 and increases the clearance of midazolam, a CYP3A4 substrate. The maximum concentration of midazolam was decreased by 31% to 67%, and drug levels were decreased by 27% to 80%. However, a single dose of danshen has the opposite effect, increasing maximum concentrations of midazolam by 87%.
Severity Moderate Likelihood Possible Evidence B

Interaction 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.

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

Here's the thing with Synalgos DC (aspirin, caffeine, and dihydrocodeine): the dihydrocodeine part is a prodrug, meaning your body has to activate it to get good pain relief. CYP3A4 plays a role in how this medicine is processed, and Danshen can nudge that enzyme in two different directions. Taken steadily for a week or two, Danshen tends to speed CYP3A4 up, which could lower drug levels and leave you with weaker pain control. A single dose seems to do the opposite, briefly raising levels, which could mean more drowsiness or constipation.

Honestly, the research behind this is early and a bit mixed, so I wouldn't panic. There's also a separate concern worth mentioning: both Danshen and the aspirin here can thin the blood, which may raise bruising or bleeding risk. Please run this combination by your pharmacist or doctor before pairing them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Qiu F, Wang G, Zhang R, Sun J, et al. Effect of danshen extract on the activity of CYP3A4 in healthy volunteers. Br J Clin Pharmacol 2010;69:656-62. PubMed
  2. Qiu F, Jiang J, Ma Y, Wang G, Gao C, Zhang X, Zhang L, Liu S, He M, Zhu L, Ye Y, Li Q, Miao P. Opposite Effects of Single-Dose and Multidose Administration of the Ethanol Extract of Danshen on CYP3A in Healthy Volunteers. Evid Based Complement Alternat Me PubMed
Moderate

ASPIRIN

4 of 4
Theoretically, danshen may increase the levels of aspirin and the risk of bleeding.
Research in healthy adult males shows that taking a combination of danshen and kudzu with aspirin increases plasma aspirin area under the curve by approximately 3.4-fold. Animal research also shows that taking a combination of danshen and kudzu (danshen-gegen formula) with aspirin increases maximal blood levels of aspirin and salicylic acid by approximately 4-fold and 3.7-fold, respectively, without impacting blood loss. Taking danshen increases the antiplatelet activity of aspirin and might increase the side effects of aspirin.
Severity Moderate Likelihood Probable Evidence B

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

The medicine you're asking about (Synalgos DC) contains aspirin, and that's the piece that interacts with Danshen. In a study of healthy men, pairing Danshen (combined with kudzu) with aspirin raised the amount of aspirin in the blood by about 3 to 4 times. On top of that, Danshen itself can make blood platelets stickier to clump, much like aspirin does. So you're really stacking two blood-thinning effects together.

What that can look like in real life: easier bruising, nosebleeds, bleeding gums, stomach upset, or dark, tarry stools. Since this product also has dihydrocodeine and caffeine, the main worry here is the added bleeding risk, not those parts. Please don't start or stop anything on your own. Just check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Zhou L, Wang S, Zhang Z, Lau BS, Fung KP, Leung PC, Zuo Z. Pharmacokinetic and pharmacodynamic interaction of Danshen-Gegen extract with warfarin and aspirin. J Ethnopharmacol. 2012 Sep 28;143(2):648-55. PubMed
  2. Zhang Y, Yang M, Ho NJ, et al. Is it safe to take Radix Salvia Miltiorrhiza - Radix Pueraria Lobate product with warfarin and aspirin? A pilot study in healthy human subjects. J Ethnopharmacol. 2020 Nov 15;262:113151. 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

Danshen Also Interacts With Other Medications

Danshen has 122 major, 936 moderate known drug interactions in our database — the Aspirin, Caffeine, Dihydrocodeine Bitartrate one above is among them. If you take anything else, check it against the full list below.

Major 122 Moderate 936 No known interaction 1,772 (incl. Aspirin, Caffeine, Dihydrocodeine Bitartrate)
Taking anything else?

Check Another of Your Medications Against Danshen

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

Everything else you take

See Every Supplement That Interacts With Aspirin, Caffeine, Dihydrocodeine Bitartrate

This page covers Danshen only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Caffeine, Dihydrocodeine Bitartrate page lists 398 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 Ephedra (major).

By severity: 17 major · 334 moderate · 47 minor.

Open the Aspirin, Caffeine, Dihydrocodeine Bitartrate interaction page

One more smart check

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

We hold 18 real supplement products containing Danshen, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Danshen. Your product may carry other ingredients that interact with Aspirin, Caffeine, Dihydrocodeine Bitartrate too, on top of Danshen — 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 Danshen and Aspirin, Caffeine, Dihydrocodeine Bitartrate 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 Danshen
Top half

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

29 days ago today
Medication Aspirin, Caffeine, Dihydrocodeine Bitartrate
Top half

#715 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 Danshen

What is Danshen?

Danshen
  • Heart and circulation support
  • Angina (chest pain)
  • High blood pressure
  • Anxiety and stress
  • Liver health

Danshen is a root used in traditional Chinese medicine, mainly for heart and circulation problems. Some early research is promising, but the evidence is not strong enough to confirm it works for any condition, and it may affect blood clotting. Talk to a pharmacist or doctor before using it, especially if you take other medicines or have a health condition.

Read the full Danshen monograph & all interactions
Keep checking

Other Drugs & Danshen

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

122Major
936Moderate
0Minor
1,771No known interaction
122 Major 936 Moderate 1,771 No interaction
Major

122 interactions

Showing 60 of 122 major interactions — see all 122 on the Danshen page.

Moderate

936 interactions

Showing 60 of 936 moderate interactions — see all 936 on the Danshen page.

No interaction 1,771 drugs checked — show the list

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

Showing the 60 most looked-up of 1,771 medications checked with no known interaction — see the full Danshen list.

See the full Danshen interactions page
See every supplement checked against Aspirin, Caffeine, Dihydrocodeine Bitartrate, 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
Danshen monograph › Uses, safety, and every drug interaction in one place Aspirin, Caffeine, Dihydrocodeine Bitartrate supplement interactions › Every supplement checked against Aspirin, Caffeine, Dihydrocodeine Bitartrate, 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 Danshen and Aspirin, Caffeine, Dihydrocodeine Bitartrate Together: Common Questions

Can you take Danshen with Aspirin, Caffeine, Dihydrocodeine Bitartrate?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 4 interactions listed for Danshen and Aspirin, Caffeine, Dihydrocodeine Bitartrate?
Aspirin, Caffeine, Dihydrocodeine Bitartrate belongs to more than one drug category, and Danshen interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Danshen and Aspirin, Caffeine, Dihydrocodeine Bitartrate interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Aspirin, Caffeine, Dihydrocodeine Bitartrate and Danshen?

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.