conjugated equine estrogens
Trade name: Premarin
Animal productapproved
Approved
May 8, 1942
Conjugated estrogens (CEs), or conjugated equine estrogens (CEEs), sold under the brand name Premarin among others, is an estrogen medication which is used in menopausal hormone therapy and for various other indications. It is a mixture of the sodium salts of estrogen conjugates found in horses, such as estrone sulfate and equilin sulfate. CEEs are available in the form of both natural preparations manufactured from the urine of pregnant mares and fully synthetic replications of the natural preparations. They are formulated both alone and in combination with progestins such as medroxyprogesterone acetate. CEEs are usually taken by mouth, but can also be given by application to the skin or vagina as a cream or by injection into a blood vessel or muscle. — Wikipedia
Clinical trial activity
86 trials · 83 clinical orgs · 9 marketing orgs
Phase 1
20
Phase 2
38
Phase 3
24
Phase 4
19
Earliest trial started Sep 1, 1987 (NCT00000466)
Timeline
1940s
- May 8, 1942
Earliest FDA Approval
1950s
- May 31, 1957
American Home Products — Marketing Organization
1980s
- Jan 1, 1987
Earliest Phase 3 Sponsor(trial)
1990s
- Dec 30, 1994
Wyeth — NDA Secondary Org
- Jan 1, 1996
Earliest Phase 2 Sponsor(trial)
- Mar 24, 1999
Aspen Pharmaceuticals — NDA Secondary Org
2000s
- Dec 20, 2004
Duramed Research — NDA Secondary Org
- Dec 20, 2004
Barr Laboratories — NDA Secondary Org
- Jan 1, 2005
- Nov 28, 2008
Teva — NDA Secondary Org
2010s
- Oct 3, 2013
Pfizer — NDA Secondary Org
2020s
- Oct 15, 2025
Novast Labs — Marketing Organization
Indications
Approved for
Studied for
- Amenorrhea · Phase 2
- Arteriosclerosis · Phase 4
- Arthralgia · Phase 2
- Atherosclerosis · Phase 2
- Atrophic Vaginitis · Phase 4
- Atrophy · Phase 3
- Blood Glucose · Phase 4
- Bone Diseases · Phase 3
- Brain Injuries, Traumatic · Phase 2
- Breast Neoplasms · Phase 3
- Cardiovascular Diseases · Phase 3
- Cognitive Dysfunction · Phase 2
- Coronary Artery Disease · Phase 3
- Coronary Disease · Phase 3
- Cystocele · Phase 4
- Depression · Phase 4
- Diabetes Mellitus · Phase 3
- Endometrial Hyperplasia · Phase 4
- Endometrial Neoplasms · Phase 3
- Estrogen Replacement Therapy · Phase 1
- Estrogens · Phase 4
- General Surgery · Phase 4
- Healthy Volunteers · Phase 1
- Heart Diseases · Phase 3
- Hematuria · Phase 4
- Hormone Replacement Therapy · Phase 3
- Hot Flashes · Phase 3
- Hypercholesterolemia · Phase 3
- Hypertension · Phase 3
- Lupus Erythematosus, Systemic · Phase 4
- Menopause · Phase 4
- Metrorrhagia · Phase 1
- Myocardial Ischemia · Phase 3
- Obesity · Phase 4
- Osteoporosis · Phase 3
- Osteoporosis, Postmenopausal · Phase 1
- Parkinson Disease · Phase 2
- Pelvic Floor Disorders · Phase 4
- Pelvic Organ Prolapse · Phase 4
- Pharmacokinetics · Phase 4
- Postmenopause · Phase 4
- Primary Ovarian Insufficiency · Phase 1
- Prostatic Neoplasms · Phase 2
- Reperfusion Injury · Phase 1/Phase 2
- Sexual Dysfunction, Physiological · Phase 4
- Shock, Hemorrhagic · Phase 2
- Thoracic Surgery · Phase 3
- Thrombosis · Phase 3
- Urinary Bladder, Overactive · Phase 4
- Urinary Tract Infections · Phase 4
- Uterine Diseases · Phase 2
- Uterine Prolapse · Phase 4
- Vaginal Diseases · Phase 3
- Vaginitis · Phase 4
- Vasomotor System · Phase 4
Mechanism of action
- Estrogen receptorAGONIST
Estrogen receptor agonist
Combination products
duavee
with bazedoxifene
pmb
with meprobamate
premphase (premarin;cycrin 14/14)
with medroxyprogesterone
Also known as premphase, prempro, prempro (premarin;cycrin)
Approval history
- approvedMay 8, 1942
Chemistry & pharmacology
- Chirality
- Single Stereoisomer
- Inorganic
- No
- Polymer
- No
- Delivery
- Oral, Topical
- Availability
- Discontinued
Oral
Yes
Parenteral
No
Topical
Yes
Black box warning
Sources
- WikipediaConjugated estrogens ↗
- NCATSIU5QR144QX ↗
- ChEMBLCHEMBL1201649 ↗
- ChEMBLCHEMBL1201467 ↗
- ChEMBLCHEMBL1201466 ↗
- NCATSJM2621P2LS ↗
Also known as
- cenestin
- cenestin
- cenestin
- cenestin
- conjugated equine estrogen
- conjugated equine estrogen
- conjugated equine estrogens
- conjugated equine estrogens
- conjugated equine estrogens
- conjugated estrogen
- conjugated estrogens
- conjugated estrogens
- conjugated estrogens
- conjugated estrogens
- conjugated estrogens
- conjugated estrogens
- conjugated estrogens
- conjugated oestrogens
- estrogenic substances, conjugated
- estrogenic substances, conjugated
- estrogenic substances, conjugated
- estrogenic substances, conjugated
- estrogenic substances, conjugated
- estrogenic substances, conjugated
- estrogens conjugated
- estrogens,conjugated
- estrogens,conjugated
- estrogens, conjugated
- estrogens, conjugated
- estrogens, conjugated
- estrogens, conjugated
- estrogens, conjugated
- estrogens, conjugated synthetic a
- estrogens, conjugated synthetic a
- estrogens, conjugated synthetic a
- estrogens, conjugated synthetic a
- estrogens, conjugated synthetic b
- estrogens, conjugated synthetic b
- estrogens, conjugated synthetic b
- oestrogens conjugated
- oestrogens conjugated
- oestrogens conjugated / bazedoxifene
- premarin
- premarin
- premarin
- premarin
- premarin
- premarin cream
- synthetic conjugated estrogens
- synthetic conjugated estrogens a
- synthetic conjugated estrogens, a
- synthetic conjugated estrogens, a
- synthetic conjugated estrogens, b
Clinical trials
| NCT ID | Phase | Start date | Sponsor(s) |
|---|---|---|---|
| NCT06197295 | Phase 4 | Jun 16, 2022 | Mackay Medical College |
| NCT06479720 | Phase 4 | Jun 16, 2022 | Mackay Medical College |
| NCT04301934 | N/A | Apr 30, 2020 | Mayo Clinic |
| NCT04103476 | Phase 2 | Oct 1, 2019 | National Institute on Aging (NIA), University of Southern California |
| NCT03740009 | Phase 4 | Jan 2, 2019 | Foundation of Hope, North Carolina, University of North Carolina at Chapel Hill |
| NCT02869165 | Phase 4 | Jan 1, 2017 | University of Louisville |
| NCT03018106 | Phase 4 | Jan 1, 2017 | Emory University |
| NCT02694809 | Phase 2 | Jan 1, 2017 | National Cancer Institute (NCI), Northwestern University, Pfizer |
| NCT02431897 | Phase 4 | Dec 1, 2016 | Brown University, Pfizer, The University of Texas, Dallas, University of Alabama, Birmingham |
| NCT02838576 | Phase 2 | Nov 1, 2016 | Federal University of Rio Grande do Sul |
| NCT03663543 | Phase 1/Phase 2 (Phase 2) | Aug 26, 2016 | Pfizer, University of Pennsylvania |
| NCT02860897 | Phase 4 | Jul 1, 2016 | Case Western Reserve University |
| NCT02729701 | Phase 2 | Apr 1, 2016 | Pfizer, University of Kansas |
| NCT02691936 | N/A | Mar 1, 2016 | Foundation for Female Health Awareness, University of Rochester |
| NCT02524769 | N/A | Dec 1, 2015 | Loyola University |
| NCT02274571 | Early Phase 1 (Phase 1) | Sep 1, 2015 | University of Vermont |
| NCT02237079 | Phase 4 | Dec 1, 2014 | Tulane University |
| NCT02213757 | Phase 4 | Aug 1, 2014 | Georgetown University, Pfizer |
| NCT02033629 | Phase 3 | Aug 1, 2014 | Imam Abdulrahman Bin Faisal University |
| NCT02100553 | Phase 1 | Apr 1, 2014 | Pfizer |
Showing 20 of 86 trials
Page 1 / 5
Organizations
Research & Development (83)
| Organization | Org type | Trials | As lead sponsor | Phases | Earliest year |
|---|---|---|---|---|---|
| Pfizer | For profit | 29 | 23 | 4 | 2002 |
| Wyeth | For profit | 19 | 0 | 3 | 1992 |
| National Heart, Lung, and Blood Institute (NHLBI) | Government | 5 | 3 | 2 | 1987 |
| Duramed Research | For profit | 4 | 4 | 2 | 2004 |
| Harvard University | Academic/Hospital | 4 | 2 | 3 | 2002 |
| National Cancer Institute (NCI) | Government | 4 | 0 | 3 | 1997 |
| National Institute on Aging (NIA) | Government | 4 | 1 | 3 | 1987 |
| The University of Texas, Dallas | Academic/Hospital | 4 | 4 | 2 | 2009 |
| University of Washington | Academic/Hospital | 4 | 0 | 3 | 2005 |
| Mayo Clinic | Academic/Hospital | 3 | 1 | 2 | 2005 |
| University of California, San Francisco | Academic/Hospital | 3 | 1 | 3 | 1992 |
| Wake Forest University | Academic/Hospital | 3 | 1 | 1 | 1987 |
| Yeshiva University | Academic/Hospital | 3 | 0 | 3 | 1997 |
| Abbott | For profit | 2 | 2 | 1 | 2000 |
| American Urogynecologic Society | Academic/Hospital | 2 | 0 | 1 | 2012 |
| Columbia University | Academic/Hospital | 2 | 0 | 2 | 2005 |
| Eastern Cooperative Oncology Group | Academic/Hospital | 2 | 1 | 1 | 1997 |
| Johns Hopkins University | Academic/Hospital | 2 | 1 | 2 | 1996 |
| Kronos Longevity Research Institute | Academic/Hospital | 2 | 1 | 2 | 2005 |
| Mackay Medical College | Academic/Hospital | 2 | 2 | 1 | 2022 |
83 organizations
Page 1 / 5
Marketing (11)
| Organization | Org type | Relationship | Date |
|---|---|---|---|
| American Home Products | For profit | NDA | — |
| American Home Products | For profit | MKTG | May 31, 1957 |
| Aspen Pharmaceuticals | For profit | NDA2 | Mar 24, 1999 |
| Barr Laboratories | For profit | NDA2 | Dec 20, 2004 |
| Duramed Research | For profit | NDA2 | Dec 20, 2004 |
| Medpointe | For profit | NDA2 | — |
| Novast Labs | For profit | MKTG | Oct 15, 2025 |
| Pfizer | For profit | NDA2 | Oct 3, 2013 |
| Teva | For profit | NDA2 | Nov 28, 2008 |
| Wyeth | For profit | SYN | May 8, 1942 |
| Wyeth | For profit | NDA2 | Dec 30, 1994 |