What Is Pyrilamine? Uses, Dosage, and What You Need to Know in 2026

Pyrilamine is one of the oldest antihistamines in clinical use — it's been around since 1949 — yet many people encounter it without realizing it because it's rarely sold alone. It appears in menstrual relief products like Midol Complete and Pamprin, as well as in cold and allergy combination syrups. Here's everything you need to know about what pyrilamine is, what it's used for, how to take it, and what precautions to follow.

What Is Pyrilamine?

Pyrilamine (also called pyrilamine maleate or mepyramine) is a first-generation antihistamine belonging to the ethylenediamine chemical class. It works by blocking histamine H1 receptors, which reduces allergy symptoms like runny nose, sneezing, itchy eyes, and hives. Unlike newer antihistamines, pyrilamine easily crosses the blood-brain barrier, which is why it causes drowsiness.

It was first patented in 1943 and introduced medically in 1949 under the brand name Neo-Antergan. It was widely used in OTC sleep aids in the 1960s and 70s, but the FDA removed it from standalone sleep products in 1989. Today it is found primarily in OTC combination products for menstrual symptoms and in some prescription combination cough and cold formulations.

What Is Pyrilamine Used For?

Pyrilamine is used in the following ways:

1. Menstrual symptoms (PMS/dysmenorrhea relief):

Pyrilamine's antihistamine and mild sedative properties help relieve bloating, irritability, and cramping in PMS combination products. Found in Midol Complete (with acetaminophen + caffeine) and Pamprin Multi-Symptom (with acetaminophen + pamabrom).

2. Allergic rhinitis (hay fever):

Pyrilamine blocks histamine at the H1 receptor, reducing nasal congestion, runny nose, sneezing, and itchy eyes associated with seasonal and perennial allergies.

3. Common cold symptoms:

Found in combination cough-cold products with phenylephrine (decongestant) and/or dextromethorphan (cough suppressant) to provide multi-symptom relief.

4. Urticaria (hives) and pruritus (itching):

Histamine H1 blockade reduces itching and hives caused by allergic reactions.

Common Brand Names and Products Containing Pyrilamine

• Midol Complete / Menstrual Complete — Acetaminophen 500 mg + Caffeine 60 mg + Pyrilamine maleate 15 mg (OTC)
• Pamprin Multi-Symptom / Premsyn PMS — Acetaminophen + Pamabrom + Pyrilamine (OTC)
• Deconsal CT — Phenylephrine 10 mg + Pyrilamine maleate 16 mg (Rx chewable tablet)
• Pyrlex — Standalone pyrilamine tablet (limited distribution)
• Various cough-cold syrups — Pyrilamine combined with phenylephrine and dextromethorphan (Deconsal DM, Codimal DM, others)

Pyrilamine Dosage

Dosage varies by product and indication:

• Midol Complete: 2 caplets (pyrilamine maleate 30 mg total) every 6 hours as needed; max 6 caplets per day; adults and children 12+
• Pamprin Multi-Symptom: Per product label — typically 2 caplets every 4-6 hours; max 8 caplets per day; adults and children 12+
• Deconsal CT (Rx): 1-2 chewable tablets every 12 hours as directed by your prescriber; adults and children 6+

Always follow the specific label instructions for your product. Do not exceed the maximum daily dose.

Who Should Not Take Pyrilamine?

Do not take pyrilamine if you:

• Are currently taking a MAOI antidepressant (phenelzine, tranylcypromine, isocarboxazid) or have taken one within the past 14 days
• Have asthma or other lower respiratory conditions (antihistamines are contraindicated for lower respiratory symptoms)
• Are allergic to pyrilamine or other ethylenediamine-class antihistamines
• Are a newborn or premature infant (high risk of anticholinergic side effects)

Is Pyrilamine a Controlled Substance?

No. Pyrilamine is not a controlled substance and is not scheduled by the DEA. It is widely available in OTC products without a prescription. However, some combination products containing pyrilamine with scheduled components (such as codeine) are controlled substances — the scheduling in those cases is due to the other ingredient, not the pyrilamine.

Where to Find Pyrilamine

OTC combination products containing pyrilamine (Midol, Pamprin) are available at most major pharmacies and grocery stores. For prescription formulations or standalone pyrilamine tablets with limited distribution, use medfinder to find which pharmacies near you have it in stock.