Drug & supplement interaction

Skullcap + Timothy Grass Pollen Allergen Extract

Timothy Grass Pollen Allergen Extract brand name: Grastek.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 20, 2026

The bottom line No known interaction

We found no known interaction between Skullcap and Timothy Grass Pollen Allergen Extract 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

Skullcap and Timothy Grass Pollen Allergen Extract

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 Timothy Grass Pollen Allergen Extract and Skullcap 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.

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.

Skullcap safety at a glance

Skullcap overall Use caution Often used short-term, but evidence is limited and product quality varies, so use with care.

Pregnancy Avoid Not enough safety data, so it is best avoided during pregnancy.

Breastfeeding Avoid Safety is unknown, so avoid while breastfeeding.

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

Still wondering about combining Timothy Grass Pollen Allergen Extract and Skullcap? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Timothy Grass Pollen Allergen Extract

Interactions in our licensed database are recorded against drug classes, not just single drug names. Timothy Grass Pollen Allergen Extract is filed under a single classification — oral drugs. Skullcap has documented interactions with 1 drug class — the most serious being cns depressants (moderate) — and none of Timothy Grass Pollen Allergen Extract’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Skullcap Does Interact With Other Medications

Skullcap has 248 moderate known drug interactions in our database — Timothy Grass Pollen Allergen Extract isn’t one of them. If you take anything else, check it against the full list below.

Moderate 248 No known interaction 2,582 (incl. Timothy Grass Pollen Allergen Extract)

Taking anything else?

Check Another of Your Medications Against Skullcap

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

What to actually watch for

What Skullcap Itself Has Been Linked To

This is not an interaction — nothing below involves Timothy Grass Pollen Allergen Extract. It is the side-effect record for Skullcap on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Skullcap, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

Memory problems Worth acting on Additional detail
“A single skullcap extract dose of 100 mg does not seem to have adverse CNS effects. However, a higher dose of 200 mg might cause sedation and cognitive impairment. One patient taking skullcap 350 mg three times daily for 2 weeks reported vivid dreams. It is unclear if this event was associated with skullcap.”

Skullcap · Natural Medicines adverse-effect record, reported in cognitive impairment.
2 sources cited

12216. Wolfson P, Hoffmann DL. An investigation into the efficacy of Scutellaria lateriflora in healthy volunteers. Altern Ther Health Med 2003;9:74-8.

91690. Brock C, Whitehouse J, Tewfik I, Towell T. American skullcap (Scutellaria lateriflora): a randomised, double-blind placebo-controlled crossover study of its effects on mood in healthy volunteers. Phytother Res 2014;28(5):692-8.
Vivid dreams or nightmares Additional detail

Recorded for Skullcap in the same Natural Medicines adverse-effect record shown under Memory problems above.
Drowsiness Additional detail

Recorded for Skullcap in the same Natural Medicines adverse-effect record shown under Memory problems above.

Everything above comes from the Natural Medicines adverse-effect record for Skullcap — expand a row for the licensed statement it rests on. We haven’t matched Timothy Grass Pollen Allergen Extract to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Timothy Grass Pollen Allergen Extract.

From our Q&A

Questions About Skullcap or Timothy Grass Pollen Allergen Extract

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Skullcap or Timothy Grass Pollen Allergen Extract, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Timothy Grass Pollen Allergen Extract

This page covers Skullcap only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Timothy Grass Pollen Allergen Extract page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Timothy Grass Pollen Allergen Extract page

“A daily under-the-tongue allergy tablet might seem like an odd match for supplement trouble, but timothy grass pollen allergen extract (Grastek) has 17 herbal and supplement ingredients flagged against it, and this is a list that earns real caution, mainly for one entry. Activated charcoal, the sole major-rated interaction, binds many…”

Reviewed by 2 · Jul 18, 2026

Open the Timothy Grass Pollen Allergen Extract interaction page

One more smart check

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

We hold 926 real supplement products containing Skullcap, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Skullcap. Even though Skullcap itself has no known interaction with Timothy Grass Pollen Allergen Extract, 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 Skullcap and Timothy Grass Pollen Allergen Extract 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 Skullcap

Top 25%

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

29 days ago today

Medication Timothy Grass Pollen Allergen Extract

Top 25%

#498 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.
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Skullcap reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Skullcap and Timothy Grass Pollen Allergen Extract records this page draws on were last updated July 10, 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Skullcap

What is Skullcap?

Anxiety and stress
Trouble sleeping
Nervous tension
Muscle spasms
General relaxation

American skullcap is an herb traditionally used to calm anxiety and promote relaxation, but solid human evidence is very limited. It is generally considered relatively safe for short-term use in healthy adults, though it should be avoided in pregnancy and breastfeeding and used cautiously because of possible liver concerns and product mislabeling.

Scutellaria lateriflora · Lamiaceae · Above-ground parts (leaves, stems, and flowers) · Tea, capsules, tinctures, liquid extracts, dried herb

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

Skullcap: dosing

There is no official, standardized dose for American skullcap. The right amount can vary depending on the product and the form (tea, capsule, or tincture).The safest approach is to follow the directions on the product label and not take more than recommended.

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

Read the full Skullcap monograph & all interactions

Keep checking

Other Drugs & Skullcap

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

0Major

248Moderate

0Minor

2,581No known interaction

248 Moderate 2,581 No interaction

Moderate

248 interactions

Showing 60 of 248 moderate interactions — see all 248 on the Skullcap page.

No interaction 2,581 drugs checked — show the list

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

Showing the 60 most looked-up of 2,581 medications checked with no known interaction — see the full Skullcap list.

See the full Skullcap interactions page

See every supplement checked against Timothy Grass Pollen Allergen Extract, ranked by severity

Evidence & sources

Skullcap References

The 3 references that drive our Skullcap monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Wolfson P, Hoffmann DL. An investigation into the efficacy of Scutellaria lateriflora in healthy volunteers. Altern Ther Health Med 2003;9:74-8.
Awad, R., Arnason, J. T., Trudeau, V., Bergeron, C., Budzinski, J. W., Foster, B. C., and Merali, Z. Phytochemical and biological analysis of skullcap (Scutellaria lateriflora L.): a medicinal plant with anxiolytic properties. Phytomedicine. 2003;10(8):6 PubMed
Brock C, Whitehouse J, Tewfik I, Towell T. American skullcap (Scutellaria lateriflora): a randomised, double-blind placebo-controlled crossover study of its effects on mood in healthy volunteers. Phytother Res 2014;28(5):692-8.

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 Skullcap and Timothy Grass Pollen Allergen Extract Together: Common Questions

Is it safe to take Skullcap with Timothy Grass Pollen Allergen Extract?

We do not list a known interaction between Skullcap and Timothy Grass Pollen Allergen Extract. 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.

How was the Skullcap and Timothy Grass Pollen Allergen Extract combination checked?

Interactions in our licensed database are recorded against drug classes. Timothy Grass Pollen Allergen Extract is filed under 1 classification, and Skullcap has documented interactions with 1 drug class — none of Timothy Grass Pollen Allergen Extract's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.

Does Skullcap interact with any other medications?

Yes. Skullcap has 248 documented drug interactions in our database — Timothy Grass Pollen Allergen Extract is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Does Timothy Grass Pollen Allergen Extract interact with any supplements?

Yes. Timothy Grass Pollen Allergen Extract has documented interactions with 17 supplements in our database — Skullcap is not one of them. The Timothy Grass Pollen Allergen Extract interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Skullcap monograph Uses, safety profile, and every drug interaction in one place Timothy Grass Pollen Allergen Extract supplement interactions Every supplement checked against Timothy Grass Pollen Allergen Extract, 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 References The 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Timothy Grass Pollen Allergen Extract and Skullcap?

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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.