You can freely build on The Chemical Discovery Behind the First Oral Contraceptive Pill
This patent expired in 1973. Every claim — 1 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
Syntex SA
Patent granted
1956
Expired
1973
Forward citations
19
What this patent covers
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 is now free to use
All 1 claims of US 2744122 are in the public domain. Specifically:
Claim 4: 1 4-19-NOR-17A-ETHINYLANDROSTEN-17B-01-3-ONE.
The 0 dependent claims add narrowing limitations and are also free.
What is NOT covered
Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.
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.
Who is building on this today
Pharmaceutical giants like Pfizer, Bayer, and various generic drug manufacturers continue to produce norethindrone-based medications. The foundational work by Syntex paved the way for the entire modern oral contraceptive market.
Products built on expired version of this technology
Norethindrone-based oral contraceptives
Hormone replacement therapy medications
How to cite this patent in your documentation
Syntex SA. US Patent 2744122. delta 4-19-nor-17alpha-ethinylandrosten-17beta-ol-3-one and process. Granted 1956, expired 1973. Now in the public domain.
Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.
PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.