Drug & supplement interaction

Piracetam + Letrozole

Letrozole brand name: Femara.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Piracetam and Letrozole 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Piracetam and Letrozole

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 Letrozole and Piracetam 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.

Piracetam safety at a glance

Piracetam overall Use caution It is a drug, not a true dietary supplement, and is unapproved in the U.S. with variable product quality.
Pregnancy Avoid There is not enough safety data, so avoid use during pregnancy.
Breastfeeding Avoid It may pass into breast milk and safety is unknown, so avoid use while breastfeeding.

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

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

Why No Interaction Is Listed for Letrozole

Interactions in our licensed database are recorded against drug classes, not just single drug names. Letrozole is filed under 4 classifications — including aromatase inhibitors, cytochrome p450 2c19 (cyp2c19) inhibitors, cytochrome p450 3a4 (cyp3a4) substrates. Piracetam has documented interactions with 1 drug class — the most serious being anticoagulant/antiplatelet drugs (major) — and none of Letrozole’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

Piracetam Does Interact With Other Medications

Piracetam has 122 major, known drug interactions in our database — Letrozole isn’t one of them. If you take anything else, check it against the full list below.

Major 122 No known interaction 2,708 (incl. Letrozole)
Taking anything else?

Check Another of Your Medications Against Piracetam

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

What to actually watch for

No Interaction Found — But Data Suggests Piracetam and Letrozole May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Bleeding or bruising Worth acting on Additional detail

    Piracetam

    “Orally, piracetam was reported to cause abnormally heavy menstrual bleeding in one adult.”

    Piracetam · Natural Medicines adverse-effect record, reported in bleeding.

    1 source cited
    1. 95177. Kampman K, Majewska MD, Tourian K, et al. A pilot trial of piracetam and ginkgo biloba for the treatment of cocaine dependence. Addict Behav 2003;28(3):437-48. PubMed

    Letrozole

    Listed in the ADVERSE REACTIONS section of the FDA label for Letrozole. Read the label on DailyMed ›

  • Tiredness / Headache Additional detail

    Piracetam

    “Orally, piracetam can cause neurologic symptoms. Short-term use has been rarely reported to cause drowsiness, dizziness, agitation, nervousness, anxiety, weakness, hyperkinesia, mild to moderate symptoms of depression, headache, slurred speech, behavioral changes including irritation and disinhibited behavior, confusion, lethargy, and sleep disturbance.

    In one case report, a 10-year old male with hypothyroidism takin…”

    Piracetam · Natural Medicines adverse-effect record, reported in anxiety.

    6 sources cited
    1. 95170. Malykh AG, Sadaie MR. Piracetam and piracetam-like drugs: from basic science to novel clinical applications to CNS disorders. Drugs 2010;70(3):287-312. PubMed
    2. 95181. Koskiniemi M, Van Vleymen B, Hakamies L, et al. Piracetam relieves symptoms in progressive myoclonus epilepsy: a multicentre, randomised, double blind, crossover study comparing the efficacy and safety of three dosages of oral piracetam with placebo. J Ne PubMed
    3. 95182. Fedi M, Reutens D, Dubeau F, et al. Long-term efficacy and safety of piracetam in the treatment of progressive myoclonus epilepsy. Arch Neurol 2001;58(5):781-6. PubMed
    4. 95183. Wilsher CR, Bennett D, Chase CH, et al. Piracetam and dyslexia: effects on reading tests. J Clin Psychopharmacol 1987;7(4):230-7. DOI
    5. 95186. Winblad B. Piracetam: a review of pharmacological properties and clinical uses. CNS Drug Rev. 2005;11(2):169-82. PubMed
    6. 95188. Neznamov GG, Teleshova ES. Comparative studies of Noopept and piracetam in the treatment of patients with mild cognitive disorders in organic brain diseases of vascular and traumatic origin. Neurosci Behav Physiol. 2009;39(3):311-21. PubMed

    Letrozole

    Listed in the ADVERSE REACTIONS section of the FDA label for Letrozole. Read the label on DailyMed ›

  • Dizziness Additional detail

    Piracetam

    “Orally, piracetam seems to be generally well tolerated.

    Most Common Adverse Effects:

    Orally: Constipation, gastrointestinal disturbances, hypertension, rash, weight gain.

    Serious Adverse Effects (Rare):

    Orally: Agitation, anxiety, behavioral changes, dizziness, drowsiness, hyperkinesia, sleep disturbance, slurred speech.

    Intravenously: Dizziness, weakness.”

    Piracetam · Natural Medicines adverse-effect record, reported in anxiety.

    Letrozole

    Listed in the ADVERSE REACTIONS section of the FDA label for Letrozole. Read the label on DailyMed ›

  • Nausea Additional detail

    Piracetam

    “Orally, piracetam has been rarely reported to cause gastrointestinal disturbances, such as nausea, vomiting, constipation, and burning sensation in the mouth.”

    Piracetam · Natural Medicines adverse-effect record, reported in constipation.

    3 sources cited
    1. 95181. Koskiniemi M, Van Vleymen B, Hakamies L, et al. Piracetam relieves symptoms in progressive myoclonus epilepsy: a multicentre, randomised, double blind, crossover study comparing the efficacy and safety of three dosages of oral piracetam with placebo. J Ne PubMed
    2. 95188. Neznamov GG, Teleshova ES. Comparative studies of Noopept and piracetam in the treatment of patients with mild cognitive disorders in organic brain diseases of vascular and traumatic origin. Neurosci Behav Physiol. 2009;39(3):311-21. PubMed
    3. 95246. Croisile B, Trillet M, Fondarai J, Laurent B, Mauguière F, Billardon M. Long-term and high-dose piracetam treatment of Alzheimer's disease. Neurology. 1993;43(2):301-5. PubMed

    Letrozole

    Listed in the ADVERSE REACTIONS section of the FDA label for Letrozole. Read the label on DailyMed ›

Reported for Piracetam but not commonly for Letrozole: stomach upset, trouble sleeping, a change in thyroid levels and constipation.

Effects for Letrozole come from the ADVERSE REACTIONS section of its FDA label; effects for Piracetam come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Piracetam or Letrozole

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

This page covers Piracetam only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Letrozole page lists 142 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), 7-methoxyflavone (moderate) and Acacia Rigidula (moderate).

By severity: 3 major · 99 moderate · 40 minor.

From our pharmacist’s overview on the Letrozole page

“Letrozole (Femara) is prescribed to keep hormone-driven breast cancer from returning, so a supplement that shifts its blood level can quietly undercut treatment. Give this list of 142 ingredients genuine respect, and learn the three major entries first.”

Reviewed by 2 · Jul 18, 2026

Open the Letrozole interaction page

One more smart check

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

We hold 6 real supplement products containing Piracetam, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Piracetam. Even though Piracetam itself has no known interaction with Letrozole, 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 Piracetam and Letrozole 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 Piracetam
Steady interest

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

29 days ago today
Medication Letrozole
Top 5%

#50 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 Piracetam reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Piracetam and Letrozole records this page draws on were last updated July 11, 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 Piracetam

What is Piracetam?

  • Memory and cognition ('nootropic')
  • Cognitive decline and dementia
  • Myoclonus
  • Dyslexia in children
  • Vertigo

Piracetam is a synthetic 'nootropic' drug studied mainly for cognitive decline, myoclonus, and certain neurological conditions, but evidence for boosting memory in healthy people is weak. It is a prescription medicine in many countries and is not an approved drug or dietary supplement in the United States, so quality and safety of products sold online vary. Talk to a doctor or pharmacist before using it.

Synthetic compound (not plant-derived) · Tablets, capsules, powder, oral solution

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

Piracetam: dosing

There is no established 'supplement' dose for piracetam, and recommended amounts in medical settings vary widely depending on the country and condition being treated. Because it is unapproved in the U.S. They can help you weigh the risks, especially if you have kidney issues or take other medicines. Do not assume that taking more will work better; higher amounts may increase side effects.

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

Read the full Piracetam monograph & all interactions
Medication

About Letrozole

What Is Letrozole Used For?

Brand name: Femara

Letrozole (brand name Femara) is used to treat breast cancer in postmenopausal women whose tumors are driven by estrogen. It is used in three settings: as adjuvant (after-surgery) treatment for hormone receptor positive early breast cancer; as extended adjuvant treatment for women who have already completed about five years of tamoxifen therapy; and as first- or second-line treatment for locally advanced or metastatic (spread) breast cancer.

Femara is specifically indicated for first-line treatment of hormone receptor positive or receptor-unknown locally advanced or metastatic breast cancer, and for advanced breast cancer in women whose disease has progressed after antiestrogen therapy.

See full Letrozole drug information
Keep checking

Other Drugs & Piracetam

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

122Major
0Moderate
0Minor
2,707No known interaction
122 Major 2,707 No interaction
Major

122 interactions

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

No interaction 2,707 drugs checked — show the list

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

Showing the 60 most looked-up of 2,707 medications checked with no known interaction — see the full Piracetam list.

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

Piracetam References

The 16 references that drive our Piracetam 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. Malykh AG, Sadaie MR. Piracetam and piracetam-like drugs: from basic science to novel clinical applications to CNS disorders. Drugs 2010;70(3):287-312. PubMed
  2. Ozdemir H, Akinci E, Coskun F. Comparison of the effectiveness of intravenous piracetam and intravenous dimenhydrinate in the treatment of acute peripheral vertigo in the emergency department. Singapore Med J 2013;54(11):649-52. PubMed
  3. Kampman K, Majewska MD, Tourian K, et al. A pilot trial of piracetam and ginkgo biloba for the treatment of cocaine dependence. Addict Behav 2003;28(3):437-48. PubMed
  4. Koskiniemi M, Van Vleymen B, Hakamies L, et al. Piracetam relieves symptoms in progressive myoclonus epilepsy: a multicentre, randomised, double blind, crossover study comparing the efficacy and safety of three dosages of oral piracetam with placebo. J Ne PubMed
  5. Fedi M, Reutens D, Dubeau F, et al. Long-term efficacy and safety of piracetam in the treatment of progressive myoclonus epilepsy. Arch Neurol 2001;58(5):781-6. PubMed
  6. Wilsher CR, Bennett D, Chase CH, et al. Piracetam and dyslexia: effects on reading tests. J Clin Psychopharmacol 1987;7(4):230-7. DOI
  7. Di Ianni M, Wilsher CR, Blank MS, et al. The effects of piracetam in children with dyslexia. J Clin Psychopharmacol. 1985;5(5):272-8. PubMed
  8. Winblad B. Piracetam: a review of pharmacological properties and clinical uses. CNS Drug Rev. 2005;11(2):169-82. PubMed
  9. Neznamov GG, Teleshova ES. Comparative studies of Noopept and piracetam in the treatment of patients with mild cognitive disorders in organic brain diseases of vascular and traumatic origin. Neurosci Behav Physiol. 2009;39(3):311-21. PubMed
  10. Moriau M, Crasborn L, Lavenne-Pardonge E, et al. Platelet anti-aggregant and rheological properties of piracetam. A pharmacodynamic study in normal subjects. Arzneimittelforschung. 1993;43(2):110-8.
  11. Rao MG, Holla B, Varambally S, et al. Piracetam treatment in patients with cognitive impairment. Gen Hosp Psychiatry. 2013;35(4):451.e5-6. PubMed
  12. Tuncer S, Sencan A, Aral M, Ayhan S. Piracetam-induced dysarthria: an unusual complication of antithrombotic prophylaxis after toe to finger transfer. J Reconstr Microsurg. 2011;27(9):575-6. PubMed
  13. Waters B, Resnick M, Simeon J, et al. An adverse reaction to piracetam in an hypothyroid 10 year old boy. Prog Neuropsychopharmacol. 1980;4(2):207-9. PubMed
  14. Sandyk R, Gillman MA. Piracetam causes confusion in a patient with temporal lobe epilepsy. J Am Geriatr Soc. 1985;33(4):305. PubMed
  15. Croisile B, Trillet M, Fondarai J, Laurent B, Mauguière F, Billardon M. Long-term and high-dose piracetam treatment of Alzheimer's disease. Neurology. 1993;43(2):301-5. 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 Piracetam and Letrozole Together: Common Questions

Is it safe to take Piracetam with Letrozole?
We do not list a known interaction between Piracetam and Letrozole. 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.
Do Piracetam and Letrozole have any of the same side effects?
Yes — our sources link each of them separately to 5 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Piracetam and Letrozole combination checked?
Interactions in our licensed database are recorded against drug classes. Letrozole is filed under 4 classifications, and Piracetam has documented interactions with 1 drug class — none of Letrozole'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 Piracetam interact with any other medications?
Yes. Piracetam has 122 documented drug interactions in our database — Letrozole 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 Letrozole interact with any supplements?
Yes. Letrozole has documented interactions with 142 supplements in our database — Piracetam is not one of them. The Letrozole 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

Piracetam monograph Uses, safety profile, and every drug interaction in one place Letrozole drug information The full plain-English guide to this medication Letrozole supplement interactions Every supplement checked against Letrozole, 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 16 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Letrozole and Piracetam?

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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.