Drug & supplement interaction

Phosphatidylserine + Tizanidine

Tizanidine brand names: Zanaflex, Ontralfy.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Phosphatidylserine and Tizanidine 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

Phosphatidylserine and Tizanidine

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 Tizanidine and Phosphatidylserine 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.

Phosphatidylserine safety at a glance

Phosphatidylserine overall Use caution Generally well tolerated in studies, but long-term safety is not fully established.
Pregnancy Avoid There is not enough safety information, so it is best to avoid use during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoidance is recommended.

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

Still wondering about combining Tizanidine and Phosphatidylserine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Tizanidine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Tizanidine is filed under 6 classifications — including skeletal muscle relaxants, qt interval-prolonging drugs, cytochrome p450 1a2 (cyp1a2) substrates. Phosphatidylserine has documented interactions with 2 drug classes — the most serious being anticholinergic drugs (moderate) and cholinergic drugs (moderate) — and none of Tizanidine’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

Phosphatidylserine Does Interact With Other Medications

Phosphatidylserine has 219 moderate known drug interactions in our database — Tizanidine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 219 No known interaction 2,611 (incl. Tizanidine)
Taking anything else?

Check Another of Your Medications Against Phosphatidylserine

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

What to actually watch for

What Phosphatidylserine Itself Has Been Linked To

This is not an interaction — nothing below involves Tizanidine. It is the side-effect record for Phosphatidylserine on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Phosphatidylserine, this list is the first place to look.

  • Bloating or gas / Stomach upset / Nausea Additional detail

    “Orally, phosphatidylserine can cause gastrointestinal upset such as flatulence or nausea. Gastrointestinal upset can occur at doses of 200-300 mg/day.”

    Phosphatidylserine · Natural Medicines adverse-effect record, reported in flatulence.

    5 sources cited
    1. 7116. Pepping J. Phosphatidylserine. Am J Health-Syst Pharm 1999;56:2038,2043-4.
    2. 7121. Kidd PM. Phosphatidylserine; Membrane nutrient for memory. A clinical and mechanistic assessment. Altern Med Rev 1996;1:70-84.
    3. 15539. Schreiber S, Kampf-Sherf O, Gorfine M, et al. An open trial of plant-source derived phosphatydilserine for treatment of age-related cognitive decline. Isr J Psychiatry Relat Sci 2000;37:302-7.
    4. 68862. Monteverde, A., Gnemmi, P., Rossi, F., Monteverde, A., and Finali, G. C. Selegiline in the treatment of mild to moderate Alzheimer-type dementia. Clin.Ther 1990;12(4):315-322.
    5. 90711. Vakhapova V, Cohen T, Richter Y, Herzog Y, Kam Y, Korczyn AD. Phosphatidylserine containing omega-3 Fatty acids may improve memory abilities in nondemented elderly individuals with memory complaints: results from an open-label extension study. Dement Geri PubMed
  • Trouble sleeping / Headache Additional detail

    “Orally, phosphatidylserine can cause insomnia. Insomnia is more likely to occur with a higher dose of 600 mg. Headache has also been reported.”

    Phosphatidylserine · Natural Medicines adverse-effect record, reported in cluster headache.

    3 sources cited
    1. 7121. Kidd PM. Phosphatidylserine; Membrane nutrient for memory. A clinical and mechanistic assessment. Altern Med Rev 1996;1:70-84.
    2. 68844. Pepping, J. Phosphatidylserine. Am J Health Syst.Pharm. 10-15-1999;56(20):2038, 2043-2038, 2044.
    3. 90711. Vakhapova V, Cohen T, Richter Y, Herzog Y, Kam Y, Korczyn AD. Phosphatidylserine containing omega-3 Fatty acids may improve memory abilities in nondemented elderly individuals with memory complaints: results from an open-label extension study. Dement Geri PubMed

Everything above comes from the Natural Medicines adverse-effect record for Phosphatidylserine — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Tizanidine’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Tizanidine column appears here.

From our Q&A

Questions About Phosphatidylserine or Tizanidine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Phosphatidylserine or Tizanidine, 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 Tizanidine

This page covers Phosphatidylserine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tizanidine page lists 143 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 11 major · 101 moderate · 31 minor.

Open the Tizanidine interaction page

One more smart check

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

We hold 1,754 real supplement products containing Phosphatidylserine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Phosphatidylserine. Even though Phosphatidylserine itself has no known interaction with Tizanidine, 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 Phosphatidylserine and Tizanidine 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 Phosphatidylserine
Top 10%

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

29 days ago today
Medication Tizanidine
Top 25%

#602 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 Phosphatidylserine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Phosphatidylserine and Tizanidine 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 .
Supplement

About Phosphatidylserine

What is Phosphatidylserine?

Phosphatidylserine
  • Memory and cognitive support
  • Age-related cognitive decline
  • Attention and focus (ADHD)
  • Mental performance under stress
  • Exercise recovery

Phosphatidylserine is a natural fat-like compound found in cell membranes, especially in the brain, and it is sold mainly to support memory and thinking. Some research suggests possible benefits for age-related memory problems, but the evidence is limited and far from conclusive. It is generally well tolerated, but check with your pharmacist or doctor before using it, especially during pregnancy or breastfeeding.

Phospholipid derived from soy lecithin, sunflower lecithin, or (historically) bovine brain · Capsules, softgels, tablets, powders

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

Phosphatidylserine: dosing

There is no official standardized dose for phosphatidylserine. Amounts used in studies have varied, and the right amount for any individual is not well established.The safest approach is to follow the dose printed on the product label and not exceed it. Taking it earlier in the day may help reduce the chance of sleep problems.

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

Read the full Phosphatidylserine monograph & all interactions
Medication

About Tizanidine

What Is Tizanidine Used For?

Brand names: Zanaflex, Ontralfy

Tizanidine — available as tablets, capsules, and as the oral solution Ontralfy — is used to manage spasticity (abnormal muscle stiffness or spasms). Because it works for a relatively short window of time, it is typically scheduled around the activities when spasm relief matters most.

Ontralfy (oral solution) and Zanaflex capsules are specifically indicated for the treatment of spasticity in adults. Other tizanidine tablets and capsules are indicated for the management of spasticity more broadly.

Most-Reported Side Effects for Tizanidine

From FAERS, the FDA’s public side-effect reporting system (41,177 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 3,191 reports
Nausea 3,007 reports
Headache 2,695 reports
Fall 2,309 reports
Diarrhea 1,970 reports
See full Tizanidine drug information
Keep checking

Other Drugs & Phosphatidylserine

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

0Major
219Moderate
0Minor
2,610No known interaction
219 Moderate 2,610 No interaction
Moderate

219 interactions

Showing 60 of 219 moderate interactions — see all 219 on the Phosphatidylserine page.

No interaction 2,610 drugs checked — show the list

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

Showing the 60 most looked-up of 2,610 medications checked with no known interaction — see the full Phosphatidylserine list.

See the full Phosphatidylserine interactions page
See every supplement checked against Tizanidine, ranked by severity
Evidence & sources

Phosphatidylserine References

The 9 references that drive our Phosphatidylserine 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.

  1. Crook T, Petrie W, Wells C, Massari DC. Effects of phosphatidylserine in Alzheimer's disease. Psychopharmacol Bull 1992;28:61-6.
  2. Pepping J. Phosphatidylserine. Am J Health-Syst Pharm 1999;56:2038,2043-4.
  3. Kidd PM. Phosphatidylserine; Membrane nutrient for memory. A clinical and mechanistic assessment. Altern Med Rev 1996;1:70-84.
  4. Kim HY, Akbar M, Lau A, et al. Inhibition of neuronal apoptosis by docosahexaenoic acid (22:6n-3). Role of phosphatidylserine in antiapoptotic effect. J Biol Chem 2000;275:35215-23.. PubMed
  5. Zanotti A, Valzelli L, Toffano G. Chronic phosphatidylserine treatment improves spatial memory and passive avoidance in aged rats. Psychopharmacology (Berl) 1989;99:316-21.. PubMed
  6. Schreiber S, Kampf-Sherf O, Gorfine M, et al. An open trial of plant-source derived phosphatydilserine for treatment of age-related cognitive decline. Isr J Psychiatry Relat Sci 2000;37:302-7.
  7. Pepping, J. Phosphatidylserine. Am J Health Syst.Pharm. 10-15-1999;56(20):2038, 2043-2038, 2044.
  8. Monteverde, A., Gnemmi, P., Rossi, F., Monteverde, A., and Finali, G. C. Selegiline in the treatment of mild to moderate Alzheimer-type dementia. Clin.Ther 1990;12(4):315-322.
  9. Vakhapova V, Cohen T, Richter Y, Herzog Y, Kam Y, Korczyn AD. Phosphatidylserine containing omega-3 Fatty acids may improve memory abilities in nondemented elderly individuals with memory complaints: results from an open-label extension study. Dement Geri PubMed

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 Phosphatidylserine and Tizanidine Together: Common Questions

Is it safe to take Phosphatidylserine with Tizanidine?
We do not list a known interaction between Phosphatidylserine and Tizanidine. 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 Phosphatidylserine and Tizanidine combination checked?
Interactions in our licensed database are recorded against drug classes. Tizanidine is filed under 6 classifications, and Phosphatidylserine has documented interactions with 2 drug classes — none of Tizanidine'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 Phosphatidylserine interact with any other medications?
Yes. Phosphatidylserine has 219 documented drug interactions in our database — Tizanidine 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 Tizanidine interact with any supplements?
Yes. Tizanidine has documented interactions with 143 supplements in our database — Phosphatidylserine is not one of them. The Tizanidine 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

Phosphatidylserine monograph Uses, safety profile, and every drug interaction in one place Tizanidine drug information The full plain-English guide to this medication Tizanidine supplement interactions Every supplement checked against Tizanidine, 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 9 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Tizanidine and Phosphatidylserine?

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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.