Levonorgestrel-only emergency contraception was introduced under the brand name Postinor by 1978. Ho and Kwan published the first study comparing levonorgestrel only and the Yuzpe regimen as methods of emergency contraception in 1993 and found that they had similar effectiveness but that levonorgestrel alone was better-tolerated. In relation to this, the Yuzpe regimen has largely been replaced as a method of emergency contraception by levonorgrestrel-only preparations. Levonorgestrel-only emergency contraception was approved in the United States under the brand name Plan B in 1999, and has also been marketed widely elsewhere throughout the world under other brand names such as Levonelle and NorLevo in addition to Postinor. In 2013, the Food and Drug Administration approved Plan B One-Step for sale over-the-counter in the United States without a prescription or age restriction.Levonorgestrel has also been introduced for use as a progestogen-only intrauterine device under the brand names Mirena and Skyla among others, as a progestogen-only birth control implant under the brand names Norplant and Jadelle, as a combined oral tablet with estradiol valerate for menopausal hormone therapy under the brand name Klimonorm, and as a combined transdermal patch with estradiol for menopausal hormone therapy under the brand name Climara Pro. Ester prodrugs of levonorgestrel such as levonorgestrel acetate and levonorgestrel butanoate have been developed and studied as other forms of birth control such as long-acting progestogen-only injectable contraceptives and contraceptive vaginal rings, but have not been marketed for medical use.
Heather may refer to:

Plants
The heather family, or Ericaceae, particularly:
Common heather or ling, Calluna
Various species of the genus Cassiope
Various species of the genus Erica

Name
Heather (given name)
Heather (surname)

Arts and media
Heathers, a 1989 film directed by Michael Lehmann
Heathers: The Musical, a musical by Laurence OKeefe based on the film
Heathers (TV series), a 2018 television series based on the film
"Heather" (The Secret Circle), a television episode

Music
Heathers (band), an acoustic singing duo from Ireland
"Heather" (Beatles song), an unreleased 1968 song by Paul McCartney and Donovan
"Heather" (Conan Gray song), a 2020 song by American singer Conan Gray
"Heather", a song from fusion drummer Billy Cobhams 1974 album Crosswinds
"Heather", a 2001 song by Paul McCartney from the album Driving Rain
"Heather", a song from Patent Pending by Heavens
"Heather", a version of the Johnny Pearson song, "Autumn Reverie", which appeared on the Carpenters album Now & Then
”Heather”, a song from I Know Leopard’s album Love is a Landmine

Places
Heather, Leicestershire, a village in England
Heather Preceptory, a preceptory of the Knights Hospitaller, established in the above village
Heather St Johns Football Club, an English football club based in the above village
Heather, Missouri, a community in the United States
Heather, Washington, an unincorporated community in the United States

Other uses
Heather (fabric), interwoven yarns of mixed colours producing muted greyish shades with flecks of colour
Heather (yacht), the original name of the yacht USS Sea Gull, built in 1902
Heather, brand name of a progestogen-only pill containing norethisterone (norethindrone)

See also
Heath (disambiguation)
Heather Hills (disambiguation)
Hurricane Heather