Deslorelin
Deslorelin acetate
Also known as: SucroMate · Ovuplant · Suprelorin · GnRH analog · Gonadorelin analog · Deslorelin acetate
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Contraceptive in male dogs | 4.7 mg implant SC every 6 months OR 9.4 mg implant SC every 12 months | SC | q6mo or q12mo | Continuous | 🌎 NA |
| Temporary chemical castration | 1 implant (4.7 mg or 9.4 mg) per male dog | SC | repeat after 6 or 12 months | 6 to 12 months depending on implant size | 🌍 EU |
- Contraceptive in male dogs: Implant in loose skin between lower neck and lumbar area; avoid implanting into fat. Pregnant women should not administer the implant.
- Temporary chemical castration: Dogs <10 kg may take up to 18 months to recover testosterone. Separation from females in heat required for first 6 weeks.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Temporary chemical castration | 1 implant (4.7 mg) per male cat | SC | once | 2-4 years | 🌍 EU |
- Temporary chemical castration: Causes chemical castration for 2-4 years in tom cats.
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Induction of ovulation (follicle 30-40 mm in diameter) | 1.8 mg (1 mL) | IM | Once | Single dose | 🌎 NA |
| Induction of ovulation (follicle >30 mm in diameter) | 1 implant (2.1 mg) | SC | Once | Remove after 48h | 🌎 NA |
- Induction of ovulation (follicle 30-40 mm in diameter): Administer in the neck. Shake vial well before drawing into syringe.
- Induction of ovulation (follicle >30 mm in diameter): Implant SC in the neck. Remove after approx 48 hours to prevent prolonged interovulatory interval. Alternative: Infuse 1 mL lidocaine into vulvar edge, insert implant beneath epithelium. Squeeze out after ovulation.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Deslorelin acetate is a potent synthetic analog of gonadotropin-releasing hormone (GnRH). It is utilized in veterinary medicine for two seemingly opposite purposes, depending on the formulation and duration of exposure:
- Short-term use (Ovulation Induction): In mares, short-acting injectable suspensions or removable implants are used to induce and precisely time ovulation, facilitating successful breeding.
- Long-term use (Medical Castration/Contraception): Sustained-release implants provide continuous GnRH stimulation, which ultimately suppresses the reproductive axis. This is used for reversible contraception in male dogs, and off-label for managing benign prostatic hyperplasia (BPH) and incontinence in ovariectomized dogs.
Clinical Pearl: Although not explicitly labeled in all regions, deslorelin implants (Suprelorin) are widely considered the gold standard treatment for adrenal gland disease in ferrets and are frequently used off-label for reproductive control in exotic species and zoo animals.
Mechanism of action
Deslorelin acts as an agonist at GnRH receptors in the anterior pituitary gland. Its clinical effect depends entirely on the duration of administration:
- Acute Administration (Flare Effect): Initial binding to GnRH receptors stimulates a rapid surge in the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
- Pathway: Deslorelin → Pituitary GnRH receptors → ↑ LH/FSH surge → Induction of ovulation (in mares with mature follicles >30 mm).
- Continuous Administration (Downregulation): When provided as a sustained-release implant, the continuous presence of the GnRH analog overstimulates the receptors.
- Pathway: Continuous deslorelin → Internalization and downregulation of GnRH receptors → Profound suppression of LH and FSH secretion → Decreased production of gonadal steroids (testosterone/estrogen) → Reversible chemical castration/contraception.
Safety & warnings
Contraindications
- Known hypersensitivity to deslorelin
- Horses intended for human consumption
- Intravenous (IV) administration
- Administration by pregnant women (implants)
Adverse effects
- Local swelling, pain, and elevated skin temperature at the injection/implant site (usually resolves within 5 days)
- Prolonged interovulatory period in mares if the 2.1 mg implant is not removed
- Initial transient increase in sexual behavior or clinical signs (flare effect) before suppression occurs (with long-acting implants)
Precautions
Important Handling Warning: Pregnant women should not handle or administer deslorelin implants due to the risk of accidental self-injection and potential disruption of human pregnancy.
- Mares: To prevent a prolonged interovulatory interval during subsequent diestrus, it is highly recommended to remove the 2.1 mg implant after ovulation (approximately 48 hours post-insertion).
- Administration: Do not administer intravenously (IV). When implanting dogs, avoid injecting into fat; place in loose skin between the lower neck and lumbar area.
Monitoring
- Follicle size via ultrasound or rectal palpation (mares)
- Injection/implant site for severe swelling or reaction
- Resolution of clinical signs or reduction in testicular size (when used for contraception in dogs)
Pharmacokinetics
Absorption
In horses (2.1 mg implant), LH and FSH peak about 12 hours after implantation. Oral dosing in dogs (100 mcg/kg) demonstrated no increase in LH or FSH.
Elimination
In horses, LH and FSH return to pretreatment levels approximately 3-4 days after implantation.
Overdose
In mares receiving a single IM injection at 10X the recommended dose (18 mg), moderate tremors and hives were observed 6 hours after injection in one out of eight horses. If an inadvertent additional implant is administered, it should be removed upon detection if within 96 hours of implantation.
Available products
Formulations
- Suspension for Injection: 1.8 mg/mL
- Subcutaneous Implant: 2.1 mg
- Subcutaneous Implant: 4.7 mg
- Subcutaneous Implant: 9.4 mg
Veterinary
- Deslorelin Suspension for Injection 1.8 mg/mL (SucroMate Equine)
- Deslorelin 2.1 mg cylindrical implant (Ovuplant)
- Deslorelin Implants 4.7 mg (Suprelorin-6)
- Deslorelin Implants 9.4 mg (Suprelorin-12)
Regulatory status
Approved for induction of temporary infertility in male dogs, male cats, and male ferrets.
POM-V (Prescription Only Medicine - Veterinarian)
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Deslorelin implants and injectable suspensions must be stored refrigerated (2-8°C or 36-46°F).
Client information
For Horse Owners (Ovulation Induction):
- This medication helps precisely time your mare's ovulation to optimize breeding success.
- You may notice mild swelling or sensitivity at the injection site, which usually goes away within 5 days.
- If an implant is used, your veterinarian may need to remove it a couple of days later to ensure your mare's future heat cycles remain normal.
For Dog Owners (Medical Contraception):
- This implant acts as a "chemical castration," temporarily stopping sperm production and lowering testosterone.
-
Note: You might see a temporary increase in male behaviors (like mounting or marking) for the first few weeks before the hormone levels drop. This is normal.
- The implant slowly dissolves and does not need to be removed unless a severe reaction occurs.
- Safety Warning: Pregnant women should not handle or be involved in the administration of this implant.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.