Drug & supplement interaction

Smooth Alder + Siltuximab

Siltuximab brand name: Sylvant.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Smooth Alder and Siltuximab 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.

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Interaction report

Smooth Alder and Siltuximab

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 Siltuximab and Smooth Alder 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Smooth Alder at all — not against Siltuximab, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Smooth Alder safety at a glance

Smooth Alder overall Not established There is very little research on its safety in humans, so caution is warranted.
Pregnancy Avoid Safety has not been studied, so it is best avoided during pregnancy.
Breastfeeding Avoid No safety data exists for nursing, so avoid use while breastfeeding.

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

Still wondering about combining Siltuximab and Smooth Alder? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Siltuximab’s Own FDA Label Lists

This is not an interaction — none of it involves Smooth Alder. These are the most notable effects listed in the ADVERSE REACTIONS section of Siltuximab’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 7 of them are worth acting on rather than waiting out — marked below.

  • A low platelet count Worth acting on
  • Kidney problems Worth acting on
  • Raised blood pressure Worth acting on
  • A severe allergic reaction Worth acting on
  • A low white blood cell count Worth acting on
  • A higher chance of infection Worth acting on
  • An allergic reaction Worth acting on
  • Heartburn
  • Dry skin
  • Weight gain

Showing the 10 most notable of 23 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Siltuximab. Read the label on DailyMed › Smooth Alder’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Smooth Alder side to compare — that is a limit of the record, not a statement that Smooth Alder has no side effects.

Everything else you take

See Every Supplement That Interacts With Siltuximab

This page covers Smooth Alder only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Siltuximab page lists 121 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate), Adrafinil (moderate) and African Wild Potato (moderate).

By severity: 2 major · 87 moderate · 32 minor.

From our pharmacist’s overview on the Siltuximab page

“Genuine care is warranted with siltuximab (Sylvant), the infusion for multicentric Castleman disease, and the place to start is its two major-rated interactions: grapefruit and St. John's wort.”

Reviewed by 2 · Jul 18, 2026

Open the Siltuximab interaction page

One more smart check

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

We hold 2 real supplement products containing Smooth Alder, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Smooth Alder. Even though Smooth Alder itself has no known interaction with Siltuximab, 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 Smooth Alder and Siltuximab 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 Smooth Alder
Steady interest

#1,350 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Siltuximab
Steady interest

#2,767 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. Smooth Alder is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Smooth Alder reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Smooth Alder and Siltuximab records this page draws on were last updated June 22, 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 Smooth Alder

What is Smooth Alder?

  • Skin irritation and wounds
  • Sore throat and mouth rinse
  • Digestive complaints
  • Astringent for inflammation
  • Traditional fever remedy

Smooth Alder is a North American shrub used in traditional and folk medicine, mainly as an astringent for skin and mouth complaints. Modern scientific evidence supporting any health benefit is very limited, so it should be used cautiously and never as a substitute for proven treatments.

Alnus serrulata · Betulaceae · Bark, leaves, and sometimes cones · Tea, decoction, tincture, topical wash

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

Smooth Alder: dosing

There is no established standardized dose for Smooth Alder. It has been used traditionally as a tea or topical wash made from the bark or leaves, but reliable, tested dosing guidelines do not exist.If you choose to use a product, follow the directions on the label and do not exceed them.

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

Read the full Smooth Alder monograph & all interactions
Medication

About Siltuximab Injection

What Is Siltuximab Injection Used For?

Brand name: Sylvant

Sylvant (siltuximab) injection is approved to treat multicentric Castleman's disease (MCD) — a rare disorder involving abnormal lymph node growth driven by an overactive immune signal called IL-6. It is specifically approved for patients who test negative for both HIV and HHV-8 (human herpesvirus-8).

Sylvant has not been studied in patients with MCD who are HIV-positive or HHV-8-positive, because it does not block the form of IL-6 produced by those viruses.

See full Siltuximab Injection drug information
Keep checking

Other Drugs & Smooth Alder

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Smooth Alder References

The 2 sources that drive our Smooth Alder monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Smooth Alder is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Herbs at a Glance — NIH NCCIH Source
  2. Herbs and Supplements — MedlinePlus Source

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 Smooth Alder and Siltuximab Together: Common Questions

Is it safe to take Smooth Alder with Siltuximab?
We do not list a known interaction between Smooth Alder and Siltuximab. 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.
Does Siltuximab interact with any supplements?
Yes. Siltuximab has documented interactions with 121 supplements in our database — Smooth Alder is not one of them. The Siltuximab interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Siltuximab and Smooth Alder?

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.