History of Antihistamines: How a Sneeze Became Treatable

For most of human history, the allergic sneeze was weather — something that happened to you in June, to be endured like rain. The history of antihistamines is the story of the generation that refused that arrangement: the roughly fifteen years, between a Paris laboratory bench in the early 1930s and pharmacy shelves in the mid-1940s, in which scientists identified the chemical behind the symptoms, built molecules to block it, and turned an untreatable misery into a treatable one. It begins, as so much of allergy science does, with the substance itself.

Key takeaways

• By 1910, Henry Dale and Patrick Laidlaw had isolated and characterised histamine — the compound released in allergic attacks that produces itch, swelling and secretion, and the target every antihistamine was built to block.
• The first compound shown to antagonise histamine was piperoxan (929 F) in 1933; in 1937, Daniel Bovet and Anne-Marie Staub reported compounds that protected animals against otherwise lethal histamine doses, establishing antihistamine action as an engineerable property.
• Phenbenzamine (Antergan), described by Bernard Halpern in 1942, was the first antihistamine used clinically in humans; diphenhydramine followed in the United States in 1946, sold as Benadryl.
• The receptor the classic antihistamines block was formally designated H1 in 1966, and a second receptor, H2, was demonstrated in 1972 — each generation of the class is the 1937 Paris idea, better aimed.

The History of Antihistamines Begins With the Enemy: Histamine

By 1910, the British physiologists Henry Dale and Patrick Laidlaw had isolated and characterised histamine, a compound the body releases that dilates blood vessels, increases their permeability and produces the classic triad of the allergic attack — itch, swelling, secretion. Through the 1920s, evidence accumulated that histamine was not a bystander in allergy but a principal agent: the wheal-and-flare of a skin test, the bronchospasm of an asthma attack, the flood of hay fever all bore its signature. (The antibody that triggers its release would not be identified for another half-century — that hunt is its own story, told in our discovery of IgE.) The pharmacological question of the 1930s was whether chemistry could build a shield: a molecule that would occupy histamine's targets and blunt its effects. It is the founding question of the history of antihistamines, and it was asked most seriously in Paris.

Paris, 1933–1937: Bovet Builds the First Shields

At the Pasteur Institute, the Swiss-Italian pharmacologist Daniel Bovet worked under Ernest Fourneau in a laboratory devoted to synthetic medicinal chemistry. In 1933, screening a family of compounds called benzodioxans, Fourneau and Bovet found that one of them — piperoxan, known in the lab books as 929 F — protected guinea pigs against histamine-induced bronchospasm. It was the first synthetic compound shown to antagonise histamine. It was also, like many first drafts, too toxic for people.

Bovet pressed on with his collaborator Anne-Marie Staub. In 1937 they reported a series of phenolic-ether compounds that protected animals against otherwise lethal doses of histamine — the result that established antihistamine action as a reproducible, engineerable property rather than a lucky accident. As the review in Canadian Dermatology Today summarises it, the first antihistamines were identified in the 1930s by Bovet's group at the Pasteur Institute — the work for which, alongside his other discoveries, Bovet received the Nobel Prize in Physiology or Medicine in 1957. A university review of the period preserved at the University of Guelph dates the milestone precisely: "The first compound with antihistamine properties was synthesized by Bovet & Staub in 1937."

There is a wider frame worth setting around the Paris work, because the Pasteur laboratory of the 1930s was arguably the most productive drug-discovery shop on earth. Fourneau's department worked the same synthetic methods across problem after problem — the sulfa-drug breakthrough of the mid-1930s came out of the same institutional stable — and Bovet himself ranged across curare, the sympathetic nervous system and chemotherapy across his career. The antihistamines were not a lone flash of luck; they were what a mature medicinal-chemistry programme produces when it is pointed at a well-chosen target. Dale had given the field its target in 1910. Paris, a generation later, had the industrial method to hit it. The history of antihistamines is partly the history of those two assets finally occupying the same decade.

1942–1946: The First Medicines

Turning a guinea-pig result into a human medicine took another chemists' relay. In 1942, Bernard Halpern described phenbenzamine — marketed as Antergan — the first antihistamine used clinically in humans to treat allergies. It worked, and it was rough: the early compounds blocked histamine but also wandered into other systems, bringing sedation and side effects that made them as famous for their costs as their benefits. Refinements came quickly through the 1940s — pyrilamine (mepyramine) followed, and in the United States the chemist George Rieveschl synthesised diphenhydramine, first used in 1946 and sold as Benadryl — the molecule that carried the antihistamine idea into the American medicine cabinet. Chlorpheniramine and its siblings closed out a decade in which an entire drug class had gone from laboratory curiosity to household word.

The pattern of those first fifteen years set the template the field still follows: identify a mediator, build its antagonist, then spend generations refining the trade-off between the target you want and the systems you'd rather leave alone. The second act of refinement arrived in the 1980s, when chemists produced antihistamines engineered to act on the same histamine receptor while being kept largely out of the brain — the historical answer to the first generation's notorious drowsiness. Each wave was the same Paris idea, better aimed.

One sign of how completely the class arrived is where it ended up living. Through the post-war decades, antihistamines migrated from prescription counters to open pharmacy shelves across much of the world, until they were stocked the way households stock aspirin — bought ahead of the season, kept in the cabinet, taken for granted. A medicine class that began as a Pasteur Institute experiment became, within two generations, part of the ordinary furniture of spring. Few drug families have made the journey from laboratory exotic to household staple so completely, or so fast.

The receptor science underneath those waves has its own dated milestones, and they sharpen the story. Through the 1950s the "histamine receptor" was a pharmacologist's inference; in 1966, A.S.F. Ash and H.O. Schild formally proposed that the receptor the classic antihistamines blocked be designated H1 — the naming that retroactively christened Bovet's whole lineage "H1 antihistamines." Six years later, in 1972, James Black's team demonstrated a second receptor, H2, with its own antagonists — work that, like Bovet's, ended in a Nobel Prize (1988). Later decades added H3 and H4 to the catalogue. The point for our story is the direction of travel: what began in 1937 as "a compound that protects a guinea pig" had become, by the century's end, a precise molecular cartography of one mediator's docking sites — each generation of medicine inheriting the Paris experiment and narrowing its aim. Histamine turned out to be not one switch but a panel of them, and the antihistamines were the tools that revealed the panel, one blocked switch at a time.

From Bench to Season: What the History of Antihistamines Changed

Step back and the speed is the story. Blackley proved pollen caused hay fever in 1873; histamine was characterised in 1910; the first antihistamine compound arrived in 1937; the first medicines in 1942–46. Within one professional lifetime, the long history of pollen science went from naming a disease nobody could treat to stocking its remedy in every pharmacy in the world. The seasons, of course, continued on schedule — and still do, which is why the counts that Bovet's generation could only guess at now run daily for Chicago, New York, Los Angeles and the rest of the map on the Pollen Atlas heatmap. Questions about your own symptoms belong with the allergy specialists who practise at the modern end of this history. This article is general information only and is not medical advice.

Frequently Asked Questions

When was histamine identified?

By 1910, when the British physiologists Henry Dale and Patrick Laidlaw isolated and characterised it. Through the 1920s the evidence accumulated that histamine was a principal agent of the allergic attack — the wheal-and-flare of a skin test, the bronchospasm of asthma, the flood of hay fever all bore its signature.

Who made the first antihistamine compounds?

Daniel Bovet's laboratory at the Pasteur Institute in Paris. Screening benzodioxans in 1933, Fourneau and Bovet found piperoxan protected guinea pigs against histamine-induced bronchospasm; in 1937 Bovet and Anne-Marie Staub reported phenolic-ether compounds that protected animals against otherwise lethal doses.

What was the first antihistamine used in people?

Phenbenzamine, marketed as Antergan, described by Bernard Halpern in 1942. It worked and it was rough — the early compounds blocked histamine but also wandered into other systems, bringing sedation and side effects. Diphenhydramine followed in the United States in 1946 and was sold as Benadryl.

Why were later antihistamines less drowsy?

The second act of refinement arrived in the 1980s, when chemists produced antihistamines engineered to act on the same histamine receptor while being kept largely out of the brain — the historical answer to the first generation's notorious drowsiness. Each wave was the same Paris idea, better aimed.

The history of antihistamines is, in the end, the hinge of allergy's whole story: before it, sufferers managed geography — fleeing to the seaside, hiding indoors for six weeks, as Bostock did. After it, they managed chemistry. The sneeze stayed. The helplessness went.

**The medicines were the 1940s breakthrough; the forecasts are this one's. Free pollen counts and 5-day outlooks for cities worldwide: PollenAtlas.com.**