Prescription medication · Alpha-1 Agonist
phenylephrine
Also sold as Neo-Synephrine. This medicine temporarily relieves symptoms from a cold.
Data updated 2026-05-15
- 3,669
- FDA reportsLightly reported
- 2
- InteractionsFew interactions
- 10
- Recall records
What the data shows
phenylephrine (Neo-Synephrine) is a prescription Alpha-1 Agonist, among the least-reported drugs the FDA tracks (3,669 FDA reports), with 2 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
phenylephrine (Neo-Synephrine) is a prescription Alpha-1 Agonist. This medicine temporarily relieves symptoms from a cold.
Phenylephrine is a medicine that helps relieve cold and flu symptoms. It can reduce fever and relieve pain.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$0.05/unit
Generic Available
Yes (24 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine temporarily relieves symptoms from a cold.
Common side effects
No common side effects listed.
Key warnings
Do not take more medicine than directed, as overdose can be dangerous.
The sections below are summarized in plain English from phenylephrine's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Phenylephrine works by narrowing blood vessels in your nose and sinuses. This helps to reduce congestion and makes it easier to breathe. It also helps to reduce inflammation and pain.
How to Take It
Adults and children 12 years and over should take 30 mL every 4 hours. Do not take more than 6 doses (180 mL) in 24 hours. Only use the provided dosing cup to measure your dose. Do not use any other measuring device.
This is a plain-language summary of phenylephrine's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
It is not known if this medicine will harm your unborn baby. Talk to your doctor before taking this medicine if you are pregnant or breastfeeding.
This is a plain-language summary of phenylephrine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. Do not take a double dose to make up for the missed dose.
This is a plain-language summary of phenylephrine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store at room temperature away from moisture and heat.
Side Effects (from patient reports)
Based on 3,669 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for phenylephrine, by number of reports
- Blistering skin disorder
Blistering skin disorder
948 reports
- Swollen joint
Swollen joint
920 reports
- Pain
Pain
902 reports
- Rheumatoid arthritis
Rheumatoid arthritis
872 reports
- Inflammation around the heart
Inflammation around the heart
868 reports
- Lupus
Lupus
867 reports
- Reaction to the IV
Reaction to the IV
846 reports
- Wound
Wound
843 reports
- Burning tongue syndrome
Burning tongue syndrome
837 reports
- Inflammation of the joint lining
Inflammation of the joint lining
833 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for phenylephrine each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where phenylephrine sits
phenylephrine has more FDA adverse-event reports than 21% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is phenylephrine; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 3,669 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
3,669
Reports Mentioning Death
1,539
41.9% of reports — not proof of cause
Hospitalization Reports
1,983
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 2 | PEMPHIGUS | 948 |
| 3 | JOINT SWELLING | 920 |
| 5 | PAIN | 902 |
| 6 | RHEUMATOID ARTHRITIS | 872 |
| 7 | PERICARDITIS | 868 |
| 8 | SYSTEMIC LUPUS ERYTHEMATOSUS | 867 |
| 9 | INFUSION RELATED REACTION | 846 |
| 10 | WOUND | 843 |
| 11 | GLOSSODYNIA | 836 |
| 12 | SYNOVITIS | 833 |
| 13 | ARTHROPATHY | 822 |
| 14 | CONDITION AGGRAVATED | 822 |
| 15 | MATERNAL EXPOSURE DURING PREGNANCY | 806 |
| 16 | TYPE 2 DIABETES MELLITUS | 804 |
| 17 | HEPATIC ENZYME INCREASED | 791 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Do not take more medicine than directed, as overdose can be dangerous. Do not use this medicine in children under 12 years of age.
Known Drug Interactions
Excessive reduction of blood glucose (additive effect) [See Warnings and Precautions (5.14)] ; CNS depressant agents (including opioids, alcohol, sedatives, hypnotics) Use with caution Increased CNS depression Dietary supplements containing sympathomimetics Contraindicated Antidepressants including but not limited to: • Other MAOIs (e.g., linezolid, intravenous methylene blue, selective MAOIs) • Selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) • Tricyclic antidepressants • Amoxapine, bupropion, maprotiline, nefazodone, trazodone,...
Mechanism: Tranylcypromine blocks the enzyme that normally processes phenylephrine, leading to an extreme and unsafe increase in blood pressure.
What to do: Do not use these medicines together. Always check with your pharmacist before taking any over-the-counter cold or allergy medicines while on tranylcypromine.
Terazosin has been used concomitantly in at least 50 patients on the following drugs or drug classes: analgesic/anti-inflammatory (e.g., acetaminophen, aspirin, codeine, ibuprofen, indomethacin); antibiotics (e.g., erythromycin, trimethoprim and sulfamethoxazole); anticholinergic/sympathomimetics (e.g., phenylephrine hydrochloride, phenylpropanolamine hydrochloride, pseudoephedrine hydrochloride); antigout (e.g., allopurinol); antihistamines (e.g., chlorpheniramine); cardiovascular agents (e.g., atenolol, hydrochlorothiazide, methyclothiazide, propranolol); corticosteroids;...
Mechanism: These drugs work against each other because one relaxes blood vessels to lower blood pressure while the other narrows them to raise it. This can make your blood pressure medicine less effective.
What to do: Talk to your doctor before using these together, as your blood pressure may need to be checked more often. They may suggest a different decongestant that does not affect blood pressure.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
How often can I take this medicine?
Can children under 12 take this medicine?
What should I use to measure the dose?
Can I take more than the recommended dose?
What do I do if I miss a dose?
Can I take this medicine if I am pregnant?
How should I store this medicine?
What does this medicine treat?
How does this medicine work?
Can I use a regular spoon to measure the dose?
Does phenylephrine interact with other medications?
What drug class is phenylephrine?
Is phenylephrine safe during pregnancy?
Has phenylephrine been recalled?
Active Recalls
cGMP deviations.
Wells Pharma of Houston LLC
Incorrect Product Formulation
Fagron Compounding Services
CGMP Deviations
Park Avenue Compounding
Sub-Potent Drug: Subpotent assay results during stability testing.
Imprimis NJOF, LLC
Sub-Potent Drug: The stability batch showed a subpotent result, which does not meet the product specifications of 90.0-110.0% of the label claim.
Imprimis NJOF, LLC
Lack of Assurance of Sterility: Firm did not perform process validation.
SSM Health Care St. Louis DBA SSM St. Clare Health Center
Superpotent Drug: semi-automated IV bag filling system can malfunction and provide a double dose of drug product to IV bags.
Denver Solutions, LLC DBA Leiters Health
Superpotent Drug: semi-automated IV bag filling system can malfunction and provide a double dose of drug product to IV bags.
Denver Solutions, LLC DBA Leiters Health
Labeling: Label Mix-Up: The label of a dropper bottle mistakenly states the container is a 0.5mL single-use syringe instead of a 5 mL dropper
Fagron Compounding Services
Lack of Assurance of Sterility: FDA inspection findings resulted in concerns regarding quality control processes
Lowlite Investments, Inc. D/B/A Olympia Pharmacy
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What the FDA Data Shows for phenylephrine
The FDA label for phenylephrine (sold under brand names such as Neo-Synephrine) classifies it as a prescription-only medication in the Alpha-1 Agonist class. This medicine temporarily relieves symptoms from a cold. Labeling covers dosing, contraindications, and monitoring requirements derived from clinical trials.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 3,669 voluntary reports. The database also lists 2 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS shows a generic unit cost of $0.05.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 10 recall records on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: March 27, 2024
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages