Drug & supplement interaction

Solomon's Seal + Metformin Hydrochloride

Metformin Hydrochloride brand name: Riomet ER.

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

Solomon's Seal has a moderate interaction with Metformin Hydrochloride. Theoretically, concomitant use may enhance hypoglycemic drug effects and alter blood glucose control.

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

Solomon's Seal and Metformin Hydrochloride

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Metformin Hydrochloride

Metformin Hydrochloride falls under ANTIDIABETES DRUGS — the group Solomon's Seal interacts with.

Theoretically, concomitant use may enhance hypoglycemic drug effects and alter blood glucose control. Monitor blood glucose.
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 situation with Solomon's Seal and metformin. The concern is mostly on paper at this point. Some lab and animal work hints that compounds in this herb might have a mild blood-sugar-lowering effect of their own. If that holds true in people, layering it on top of metformin could nudge your glucose a little lower than expected. Metformin by itself rarely causes true lows, but adding something else with similar activity is the theoretical worry.

So this isn't a hard 'don't,' it's a 'keep an eye out.' Watch for signs like shakiness, sweating, dizziness, or feeling foggy, and check your numbers a bit more closely if you start the herb. Loop in your pharmacist or doctor before combining them so they can help you monitor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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

Solomon's Seal Also Interacts With Other Medications

Solomon's Seal has 85 moderate known drug interactions in our database — the Metformin Hydrochloride one above is one of them. If you take anything else, check it against the full list below.

Moderate 85 No known interaction 2,745 (incl. Metformin Hydrochloride)
Taking anything else?

Check Another of Your Medications Against Solomon's Seal

Covers the 2,830 medications we’ve checked against Solomon's Seal. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Metformin Hydrochloride

This page covers Solomon's Seal only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin Hydrochloride page lists 257 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 2 major · 217 moderate · 38 minor.

From our pharmacist’s overview on the Metformin Hydrochloride page

“Anyone taking metformin hydrochloride (Riomet ER) should treat this list with genuine care, because two of its 257 entries are rated major. Siberian cocklebur has caused severe hypoglycemia in people and should not be combined with metformin at all, and activated charcoal can adsorb the drug in the gut so less reaches your blood.”

Reviewed by 2 · Jul 18, 2026

Open the Metformin Hydrochloride interaction page

One more smart check

Taking Solomon's Seal as Part of a Dietary Supplement Product? Check It for Interactions

We hold 113 real supplement products containing Solomon's Seal, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Solomon's Seal. Your product may carry other ingredients that interact with Metformin Hydrochloride too, on top of Solomon's Seal — 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 Solomon's Seal and Metformin Hydrochloride 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 Solomon's Seal
Top half

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

29 days ago today
Medication Metformin Hydrochloride
Top 10%

#158 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 Solomon's Seal

What is Solomon's Seal?

Solomon's Seal
  • Joint and muscle discomfort
  • Tendon and ligament injuries
  • Inflammation
  • Digestive complaints
  • Skin and wound care
  • Dry cough and throat irritation

Solomon's Seal is a traditional herb whose root has long been used for joint, tendon, and muscle complaints, but high-quality human studies are largely lacking. There is not enough reliable evidence to confirm it works for any specific condition, so use it cautiously and talk with your pharmacist or doctor first.

Read the full Solomon's Seal monograph & all interactions
Keep checking

Other Drugs & Solomon's Seal

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

0Major
85Moderate
0Minor
2,744No known interaction
85 Moderate 2,744 No interaction
Moderate

85 interactions

Showing 60 of 85 moderate interactions — see all 85 on the Solomon's Seal page.

No interaction 2,744 drugs checked — show the list

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

Showing the 60 most looked-up of 2,744 medications checked with no known interaction — see the full Solomon's Seal list.

See the full Solomon's Seal interactions page
See every supplement checked against Metformin Hydrochloride, 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
Solomon's Seal monograph › Uses, safety, and every drug interaction in one place Metformin Hydrochloride supplement interactions › Every supplement checked against Metformin Hydrochloride, 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 Solomon's Seal and Metformin Hydrochloride Together: Common Questions

Can you take Solomon's Seal with Metformin Hydrochloride?
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 Solomon's Seal and Metformin Hydrochloride 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 Metformin Hydrochloride and Solomon's Seal?

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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.