# The Chemical Discovery Behind the First Oral Contraceptive Pill

> A 1952 patent for a synthetic hormone that became the active ingredient in the first effective oral contraceptive pill.

- **Patent:** US 2744122
- **Original title:** delta 4-19-nor-17alpha-ethinylandrosten-17beta-ol-3-one and process
- **Owner:** Syntex SA
- **Granted:** 1956
- **Status:** Public domain (expired)
- **Times cited:** 19
- **Field:** biotech, pharmaceutical

## What it does

The patent describes the chemical synthesis of a specific steroid compound known as 19-nor-17alpha-ethinyltestosterone, later called norethindrone. By removing a carbon atom from the standard testosterone structure and adding an ethinyl group, the inventors created a molecule that remains stable and active when taken orally. This compound mimics the body's natural progesterone, effectively suppressing ovulation to prevent pregnancy.

## What it does NOT cover

- Does not cover the final pharmaceutical delivery mechanism or pill formulation.
- Does not cover other synthetic progestins developed after this specific chemical structure.
- Does not cover the medical method of using the compound for contraception.

## The clever bit

The inventors realized that removing the C-19 methyl group from the testosterone molecule significantly increased its potency when ingested, overcoming the problem of the liver breaking down hormones before they could reach the bloodstream.

## Real-world examples

1. Norethindrone-based oral contraceptives
2. Hormone replacement therapy medications

## Why it matters

This discovery transformed reproductive health and social structures in the 20th century. It provided the chemical foundation for the birth control pill, which allowed women unprecedented control over their reproductive lives and fundamentally changed global labor markets and family planning.

## Frequently asked questions

### What does The Chemical Discovery Behind the First Oral Contraceptive Pill cover?

A 1952 patent for a synthetic hormone that became the active ingredient in the first effective oral contraceptive pill.

### Who owns patent US 2744122?

Syntex SA owns this patent, granted in 1956.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 2744122 cited by?

This patent has been cited by 19 later patents that build on its ideas.

### What problem does this patent solve?

This discovery transformed reproductive health and social structures in the 20th century. It provided the chemical foundation for the birth control pill, which allowed women unprecedented control over their reproductive lives and fundamentally changed global labor markets and family planning.

### What does this patent NOT cover?

Does not cover the final pharmaceutical delivery mechanism or pill formulation.

**Full plain-English explainer:** https://patentbrief.org/patent/us/2744122/birth-control-pill-norethindrone

**Original patent:** https://patents.google.com/patent/US2744122

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


## Related patents

Semantically similar inventions in the PatentBrief corpus:

- [Using Specific Steroid Molecules to Block Salt Retention in the Body](https://patentbrief.org/patent/us/4081538/aldosterone-antagonists) — A 1976 medical patent describing the use of 11-beta,18-oxidopregnane compounds to help the body excrete sodium by blocking the salt-retaining effects of the hormone aldosterone.
- [The Discovery of Aspartame as a Sugar Substitute](https://patentbrief.org/patent/us/3492131/aspartame-sweetener) — This 1966 patent identifies specific chemical compounds, known as aspartylphenylalanine esters, that provide intense sweetness for food and drinks without using sugar.
- [The Discovery of Lovastatin for Lowering Cholesterol](https://patentbrief.org/patent/us/4231938/statin-cholesterol-lovastatin) — A 1979 patent by Merck describing the isolation of a fermentation product from Aspergillus fungi that effectively lowers cholesterol levels in the blood.
- [How the modern internal menstrual tampon was invented](https://patentbrief.org/patent/us/1964911/tampon-applicator-haas) — Earle Haas's 1933 patent describes the first modern internal menstrual tampon, designed to be inserted into the vagina using a cardboard applicator.
- [How DuPont Invented Neoprene Synthetic Rubber](https://patentbrief.org/patent/us/1967861/neoprene-synthetic-rubber) — A 1934 patent describing the chemical process to turn chlorobutadiene into a durable, oil-resistant synthetic rubber known as Neoprene.