Drug & supplement interaction

Gamma-aminobutyric Acid (gaba) + Sildenafil Citrate

Sildenafil Citrate brand name: Viagra.

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 Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate 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

Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate

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 Sildenafil Citrate and Gamma-aminobutyric Acid (gaba) 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.

Gamma-aminobutyric Acid (gaba) safety at a glance

Gamma-aminobutyric... overall Use caution Often well tolerated short-term, but long-term safety is not well studied.
Pregnancy Avoid Not enough safety information; avoid unless your doctor advises otherwise.
Breastfeeding Avoid Not enough safety information; best to avoid while breastfeeding.

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

Still wondering about combining Sildenafil Citrate and Gamma-aminobutyric Acid (gaba)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Sildenafil Citrate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Sildenafil Citrate is filed under 6 classifications — including phosphodiesterase-5 inhibitors, vasodilators, cytochrome p450 2c9 (cyp2c9) substrates. Gamma-aminobutyric Acid (gaba) has documented interactions with 2 drug classes — the most serious being antihypertensive drugs (moderate) and cns depressants (minor) — and none of Sildenafil Citrate’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

Gamma-aminobutyric Acid (gaba) Does Interact With Other Medications

Gamma-aminobutyric Acid (gaba) has 172 moderate, 247 minor known drug interactions in our database — Sildenafil Citrate isn’t one of them. If you take anything else, check it against the full list below.

Moderate 172 Minor 247 No known interaction 2,411 (incl. Sildenafil Citrate)
Taking anything else?

Check Another of Your Medications Against Gamma-aminobutyric Acid (gaba)

Covers the 2,830 medications we’ve checked against Gamma-aminobutyric Acid (gaba). Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate 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.

  • Headache reported in 8.0% of FDA reports for Sildenafil Citrate Additional detail

    Gamma-aminobutyric Acid (gaba)

    “Orally, GABA may cause drowsiness, headache, or tiredness. Four children with cerebral palsy taking GABA had convulsions, and an unspecified number experienced motor restlessness. However, causality of these adverse effects was not clear, and the dose of GABA was not specified. Intravenously, GABA 50 mg has been associated with a "lack of alertness" in healthy female volunteers.”

    Gamma-aminobutyric Acid (gaba) · Natural Medicines adverse-effect record, reported in cerebral palsy.

    5 sources cited
    1. 5115. Cavagnini F, Invitti C, Pinto M, et al. Effect of acute and repeated administration of gamma aminobutyric acid (GABA) on growth hormone and prolactin secretion in man. Acta Endocrinol (Copenh) 1980;93:149-54.
    2. 19364. Loeb C, Benassi E, Bo, GP, et al. Preliminary evaluation of the effect of GABA and phosphatidylserine in epileptic patients. Epilepsy Res. 1987;1:209-12 . PubMed
    3. 112830. de Bie TH, Witkamp RF, Balvers MG, Jongsma MA. Effects of ?-aminobutyric acid supplementation on glucose control in adults with prediabetes: A double-blind, randomized, placebo-controlled trial. Am J Clin Nutr 2023;118(3):708-719. PubMed
    4. 19362. Gershman RN, Vasilenko MA, Iliushina GG, et al. [Gammalon in the rehabilitation in infantile cerebral palsy]. Pediatr.Akus.Ginekol. 1977;(6):26-7.
    5. 51159. Melis, G. B., Paoletti, A. M., Mais, V., and Fioretti, P. Interference of dopamine infusion on gamma-amino butyric acid (GABA)-stimulated prolactin increase. J.Endocrinol.Invest 1980;3(4):445-448.

    Sildenafil Citrate

    Listed in the ADVERSE REACTIONS section of the FDA label for Sildenafil Citrate, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Nausea reported in 5.1% of FDA reports for Sildenafil Citrate Additional detail

    Gamma-aminobutyric Acid (gaba)

    “Orally, minor throat burning has been associated with GABA in one study. In another study in which GABA was administered with phosphatidylserine, one patient experienced severe gastric distress, two patients reported moderate nausea, and one reported constipation. Children with cerebral palsy taking GABA experienced nausea and decreased appetite.”

    Gamma-aminobutyric Acid (gaba) · Natural Medicines adverse-effect record, reported in cerebral palsy.

    3 sources cited
    1. 5115. Cavagnini F, Invitti C, Pinto M, et al. Effect of acute and repeated administration of gamma aminobutyric acid (GABA) on growth hormone and prolactin secretion in man. Acta Endocrinol (Copenh) 1980;93:149-54.
    2. 19364. Loeb C, Benassi E, Bo, GP, et al. Preliminary evaluation of the effect of GABA and phosphatidylserine in epileptic patients. Epilepsy Res. 1987;1:209-12 . PubMed
    3. 19362. Gershman RN, Vasilenko MA, Iliushina GG, et al. [Gammalon in the rehabilitation in infantile cerebral palsy]. Pediatr.Akus.Ginekol. 1977;(6):26-7.

    Sildenafil Citrate

    Listed in the ADVERSE REACTIONS section of the FDA label for Sildenafil Citrate, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Gamma-aminobutyric Acid (gaba) but not commonly for Sildenafil Citrate: reduced appetite, muscle weakness, constipation and anxiety or restlessness.

Effects for Sildenafil Citrate come from the ADVERSE REACTIONS section of its FDA label; effects for Gamma-aminobutyric Acid (gaba) come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 125,272 voluntary FDA FAERS reports for Sildenafil Citrate that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Overlapping uses

What Sildenafil Citrate Is Prescribed For, and What Gamma-aminobutyric Acid (gaba) Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Sildenafil Citrate is a prescription medicine with approved uses on its FDA label. Gamma-aminobutyric Acid (gaba) is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Sildenafil Citrate is prescribed for: Sildenafil treats two distinct conditions depending on the product. Viagra (tablet) and Vybrique (dissolving oral film) are approved for erectile dysfunction (ED) — difficulty getting or keeping an erection. Generic sildenafil tablets and oral film are also approved for ED. Revatio and several generic sildenafil products (tablets, oral suspension, and injection) are used for pulmonary arterial hypertension (PAH) — high blood pressure in the arteries of the lungs — in adults to improve exercise ability and slow the disease from getting worse.

Read the rest of what Sildenafil Citrate is prescribed for

Revatio oral suspension and injection are also approved for PAH in children ages 1 to 17.

Gamma-aminobutyric Acid (gaba) has been studied for:

  • Hypertension studied, not established Gamma-aminobutyric Acid (gaba) has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Gamma-aminobutyric Acid (gaba) for hypertension

    Preliminary clinical research suggests that oral GABA may modestly reduce blood pressure in patients with mild or borderline hypertension.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Sildenafil Citrate on your own; if you are taking Gamma-aminobutyric Acid (gaba) for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Gamma-aminobutyric Acid (gaba) or Sildenafil Citrate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Gamma-aminobutyric Acid (gaba) or Sildenafil Citrate, 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 Sildenafil Citrate

This page covers Gamma-aminobutyric Acid (gaba) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Sildenafil Citrate page lists 160 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Mistletoe (major), Grapefruit (major), Hawthorn (major) and St. John's Wort (major).

Open the Sildenafil Citrate interaction page

One more smart check

Taking Gamma-aminobutyric Acid (gaba) as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,760 real supplement products containing Gamma-aminobutyric Acid (gaba), each one broken down to its full ingredient list — and combination products often carry several ingredients besides Gamma-aminobutyric Acid (gaba). Even though Gamma-aminobutyric Acid (gaba) itself has no known interaction with Sildenafil Citrate, 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 Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate 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 Gamma-aminobutyric Acid (gaba)
Top 10%

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

29 days ago today
Medication Sildenafil Citrate
Top half

#1,350 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 Gamma-aminobutyric Acid (gaba) reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate 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 Gamma-aminobutyric Acid (gaba)

What is Gamma-aminobutyric Acid (gaba)?

Gamma-aminobutyric Acid (gaba)
  • Anxiety and stress
  • Sleep problems
  • Relaxation
  • High blood pressure
  • Mood support

GABA is a calming chemical messenger (neurotransmitter) that your body makes on its own, and it is sold as a supplement for stress, anxiety, and sleep. The science behind oral GABA supplements is limited and mixed, partly because it is unclear how much swallowed GABA actually reaches the brain. It is generally well tolerated short-term, but talk with a pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or take other medicines.

Not a plant; an amino acid/neurotransmitter (made naturally in the body and produced for supplements by fermentation) · Capsules, tablets, powders, chewable tablets, gummies, drink mixes

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

Gamma-aminobutyric Acid (gaba): dosing

There is no official or standardized dose for GABA supplements. Amounts used in studies have varied widely, and there is not enough strong evidence to recommend a specific dose.The safest approach is to follow the directions on the product label and start with the lowest suggested amount.

From our Gamma-aminobutyric Acid (gaba) monograph — the full record covers uses, side effects and every documented interaction.

Read the full Gamma-aminobutyric Acid (gaba) monograph & all interactions
Medication

About Sildenafil

What Is Sildenafil Used For?

Brand name: Viagra

Sildenafil treats two distinct conditions depending on the product. Viagra (tablet) and Vybrique (dissolving oral film) are approved for erectile dysfunction (ED) — difficulty getting or keeping an erection. Generic sildenafil tablets and oral film are also approved for ED.

Revatio and several generic sildenafil products (tablets, oral suspension, and injection) are used for pulmonary arterial hypertension (PAH) — high blood pressure in the arteries of the lungs — in adults to improve exercise ability and slow the disease from getting worse. Revatio oral suspension and injection are also approved for PAH in children ages 1 to 17.

See full Sildenafil drug information
Keep checking

Other Drugs & Gamma-aminobutyric Acid (gaba)

Browse every other medication we’ve checked against Gamma-aminobutyric Acid (gaba) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
172Moderate
247Minor
2,410No known interaction
172 Moderate 247 Minor 2,410 No interaction
Moderate

172 interactions

Showing 60 of 172 moderate interactions — see all 172 on the Gamma-aminobutyric Acid (gaba) page.

Minor

247 interactions

Showing 60 of 247 minor interactions — see all 247 on the Gamma-aminobutyric Acid (gaba) page.

No interaction 2,410 drugs checked — show the list

We also checked Gamma-aminobutyric Acid (gaba) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,410 medications checked with no known interaction — see the full Gamma-aminobutyric Acid (gaba) list.

See the full Gamma-aminobutyric Acid (gaba) interactions page
See every supplement checked against Sildenafil Citrate, ranked by severity
Evidence & sources

Gamma-aminobutyric Acid (gaba) References

The 12 references that drive our Gamma-aminobutyric Acid (gaba) 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. Cavagnini F, Invitti C, Pinto M, et al. Effect of acute and repeated administration of gamma aminobutyric acid (GABA) on growth hormone and prolactin secretion in man. Acta Endocrinol (Copenh) 1980;93:149-54.
  2. Nurnberger JI Jr, Berrettini WH, Simmons-Alling S, et al. Intravenous GABA administration is anxiogenic in man. Psychiatry Res 1986;19:113-7. PubMed
  3. Gershman RN, Vasilenko MA, Iliushina GG, et al. [Gammalon in the rehabilitation in infantile cerebral palsy]. Pediatr.Akus.Ginekol. 1977;(6):26-7.
  4. Loeb C, Benassi E, Bo, GP, et al. Preliminary evaluation of the effect of GABA and phosphatidylserine in epileptic patients. Epilepsy Res. 1987;1:209-12 . PubMed
  5. Inoue K, Shirai T, Ochiai H, et al. Blood-pressure-lowering effect of a novel fermented milk containing gamma-aminobutyric acid (GABA) in mild hypertensives. Eur J Clin Nutr 2003;57:490-95.
  6. ELLIOTT, K. A. and JASPER, H. H. Gammaaminobutyric acid. Physiol Rev. 1959;39(2):383-406.
  7. Winsky-Sommerer, R. Role of GABAA receptors in the physiology and pharmacology of sleep. Eur.J.Neurosci. 2009;29(9):1779-1794.
  8. Meldrum, B. S. GABAergic mechanisms in the pathogenesis and treatment of epilepsy. Br.J.Clin.Pharmacol. 1989;27 Suppl 1:3S-11S. PubMed
  9. Loeb, C., Marinari, U. M., Benassi, E., Besio, G., Cottalasso, D., Cupello, A., Maffini, M., Mainardi, P., Pronzato, M. A., and Scotto, P. A. Phosphatidylserine increases in vivo the synaptosomal uptake of exogenous GABA in rats. Exp.Neurol. 1988;99(2):4 PubMed
  10. Melis, G. B., Paoletti, A. M., Mais, V., and Fioretti, P. Interference of dopamine infusion on gamma-amino butyric acid (GABA)-stimulated prolactin increase. J.Endocrinol.Invest 1980;3(4):445-448.
  11. Boonstra E, de Kleijn R, Colzato LS, Alkemade A, Forstmann BU, Nieuwenhuis S. Neurotransmitters as food supplements: the effects of GABA on brain and behavior. Front Psychol. 2015 Oct 6;6:1520. doi: 10.3389/fpsyg.2015.01520. eCollection 2015. PubMed
  12. de Bie TH, Witkamp RF, Balvers MG, Jongsma MA. Effects of ?-aminobutyric acid supplementation on glucose control in adults with prediabetes: A double-blind, randomized, placebo-controlled trial. Am J Clin Nutr 2023;118(3):708-719. 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 Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate Together: Common Questions

Is it safe to take Gamma-aminobutyric Acid (gaba) with Sildenafil Citrate?
We do not list a known interaction between Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate. 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 Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate have any of the same side effects?
Yes — our sources link each of them separately to 2 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.
Are Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Gamma-aminobutyric Acid (gaba) in each. That is a conversation for your prescriber, especially if Sildenafil Citrate is being adjusted to a target.
How was the Gamma-aminobutyric Acid (gaba) and Sildenafil Citrate combination checked?
Interactions in our licensed database are recorded against drug classes. Sildenafil Citrate is filed under 6 classifications, and Gamma-aminobutyric Acid (gaba) has documented interactions with 2 drug classes — none of Sildenafil Citrate'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 Gamma-aminobutyric Acid (gaba) interact with any other medications?
Yes. Gamma-aminobutyric Acid (gaba) has 419 documented drug interactions in our database — Sildenafil Citrate 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 Sildenafil Citrate interact with any supplements?
Yes. Sildenafil Citrate has documented interactions with 160 supplements in our database — Gamma-aminobutyric Acid (gaba) is not one of them. The Sildenafil Citrate 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

Gamma-aminobutyric Acid (gaba) monograph Uses, safety profile, and every drug interaction in one place Sildenafil drug information The full plain-English guide to this medication Sildenafil Citrate supplement interactions Every supplement checked against Sildenafil Citrate, 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 12 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

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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.