The estrogen patch is a delivery system for estradiol

Estradiol

Estradiol is a sex hormone. Estradiol is abbreviated E2 as it has 2 hydroxyl groups in its molecular structure. Estrone has 1 and estriol has 3 . Estradiol is about 10 times as potent as estrone and about 80 times as potent as estriol in its estrogenic effect...

, which is used as hormone replacement therapy

Hormone replacement therapy (menopause)

Hormone replacement therapy is a system of medical treatment for surgically menopausal, perimenopausal and to a lesser extent postmenopausal women...

 to treat the problems of menopause

Menopause

Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...

, such as hot flashes and vaginal dryness, or to prevent osteoporosis

Osteoporosis

Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...

. The estrogen

Estrogen

Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...

 is given transdermally

Transdermal patch

A transdermal patch is a medicated adhesive patch that is placed on the skin to deliver a specific dose of medication through the skin and into the bloodstream. Often, this promotes healing to an injured area of the body. An advantage of a transdermal drug delivery route over other types of...

 rather than via oral tablet

Tablet

A tablet is a pharmaceutical dosage form. It comprises a mixture of active substances and excipients, usually in powder form, pressed or compacted from a powder into a solid dose...

s, meaning that the estrogen patch carries similar risks and benefits that conventional forms of estrogen-only hormone replacement therapy have, but there are also important differences. For example, transdermal estrogen bypasses the liver so avoids the liver effects that occur with use of oral medications, and has slightly different effects on triglycerides and cholesterol than oral estrogens.

Administration

Applied twice weekly or weekly, depending on the brand, to fatty areas of the skin

Skin

-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...

 which crease less, preferably the lower abdomen or buttocks. Never to the breasts.

Brand names

• Alora (United States
  United States
  The United States of America is a federal constitutional republic comprising fifty states and a federal district...
  
  )
• Climara (United States)
• Dermestril (United Kingdom
  United Kingdom
  The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
  
  )
• Elleste Solo (United States)
• Esclim (United States) (Discontinued in 2005)
• Estraderm (United Kingdom)
• Estradot (United Kingdom)
• Evorel (United Kingdom)
• Fematrix (United Kingdom)
• Fempatch (United States)
• FemSeven (United Kingdom)
• Menostar (United States)
• Vivelle-Dot (Originally marketed as Vivelle (Novartis
  Novartis
  Novartis International AG is a multinational pharmaceutical company based in Basel, Switzerland, ranking number three in sales among the world-wide industry...
  
  ), but superseded by this smaller version with better adhesion in 2000. Vivelle was discontinued in 2003.)