Buserelin: veterinary dose and monograph

At a glance

Drug class

Veterinary drug

Also known as

Receptal VET, Gynarich, Pregulate, Suprefact

Species with doses

Cattle, Horses, Buffalo and Ferrets

Routes

IM

Last reviewed

1 October 2026

Indications

• True anoestrus / sub-oestrus
• Ovarian (follicular) cyst — nymphomania
• Delayed ovulation / anovulation
• Improvement of conception rate at AI
• Improvement of pregnancy rate 11–12 days post-AI
• Post-partum fertility (10–15 days post-calving)

Buserelin dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Cattle

• True anoestrus / cystic ovaries: Label-sourced (Receptal / Gynarich, 4 µg/mL): 20 µg (5 mL) per cow IM for follicular cysts or true anoestrus. Buserelin has no monograph in Papich 5e or Plumb’s — gonadorelin is the referenced GnRH alternative. Follow the local label; GnRH analogues generally carry no withdrawal.
• Conception improvement at AI: Label-sourced (Receptal / Gynarich): 10 µg (2.5 mL) IM at insemination. Not in Papich 5e or Plumb’s.
• Delayed ovulation: Label-sourced (Receptal / Gynarich): 10 µg (2.5 mL) IM at signs of oestrus. Not in Papich 5e or Plumb’s.
• Pregnancy rate improvement (day 11–12 post-AI): Label-sourced (Receptal / Gynarich): 10 µg (2.5 mL) IM on days 11–12 after AI. Not in Papich 5e or Plumb’s.

Horses

• Induction of ovulation: Label-sourced (Receptal): 20–40 µg (5–10 mL) IM. Not in Papich 5e or Plumb’s (deslorelin or hCG are the referenced ovulation inducers).

Buffalo

• Ovsynch / ovulation induction / follicular cysts: Receptal/Gynarich label buffalo with cattle: 10–20 µg (2.5–5 mL) IM as the GnRH component of Ovsynch (GnRH d0 → PGF2α d7 → GnRH d9 → AI). Widely used in buffalo fixed-time-AI programmes.

Ferrets

• Suppression of oestrus (jill): Carpenter's 6th ed (Ferret endocrine table): 1.5 µg per animal IM q24h for 2 days — GnRH analog used to suppress signs of oestrus / take an intact jill out of oestrus (an alternative to hCG).

Contraindications

Hypersensitivity. Pregnancy (avoid until pregnancy confirmed by ultrasound). Do not use in animals with luteal cysts before luteolysis is confirmed.

Species-specific warnings

Cattle: Standard ovsynch component. 10 µg IM per cow. Zero withdrawal. Refrigerate to maintain potency.

Horses: 20–40 µg IM for induction of ovulation in mares. Useful when hCG response inadequate.

Goats: Used extra-label for follicular cysts at 5–10 µg IM single.

Sheep: Used in synchronisation protocols at 5–10 µg IM.

Adverse effects

• Generally well tolerated
• Rare hypersensitivity reactions

Drug interactions

• Prostaglandin F2α (cloprostenol, dinoprost): SEQUENTIAL synergy in ovsynch protocol — GnRH day 0 → PGF2α day 7 → GnRH day 9 → AI day 10
• Progesterone (CIDR / PRID intravaginal devices): sequential synergy in PRID / CIDR-synch protocols
• Corticosteroids: theoretical inhibition of GnRH effect — limited clinical impact
• NSAIDs: no significant interaction at therapeutic doses

Pregnancy and lactation

Generally safe in established pregnancy (after maternal recognition of pregnancy ~day 16). USED routinely on day 5–7 post-AI in cattle to improve conception (supplementary CL formation). Buserelin does NOT cause abortion (unlike PGF2α). Zero withdrawal periods make it convenient for dairy.

Monitoring

• Oestrus detection at scheduled intervals — clinical response is the endpoint
• Pregnancy diagnosis at 28–42 days post-AI
• No serum monitoring needed — clinical effect is straightforward
• Zero withdrawal periods — convenient for all stages of dairy production
• Bovine follicular cysts: re-evaluate ovarian status by rectal palpation / ultrasound at 7–10 days

Toxicity and overdose

Extremely safe — wide therapeutic margin. Acute high-dose: transient sweating, mild restlessness. NO known organ toxicity at clinical doses. Repeated daily dosing can cause pituitary GnRH receptor downregulation (clinically irrelevant at standard intervals).

Management: Supportive only — overdose extremely well tolerated. No specific antidote needed. Most overdoses asymptomatic.

Clinical pearls

• OVSYNCH PROTOCOL (standard dairy reproductive management): GnRH (10 µg) day 0 → PGF2α day 7 → GnRH day 9 → timed AI day 10 — eliminates oestrus detection
• Bovine follicular cysts: 10 µg IM single — luteinises the cyst, resolves within 14–21 days
• Conception rate improvement at AI: 10 µg IM at insemination
• Day 5–7 post-AI: 10 µg IM forms supplementary CL — improves pregnancy rates 5–10%
• Equine: 20–40 µg IM at oestrus to induce ovulation — useful when mare doesn't respond to hCG
• ZERO milk / meat withdrawal — convenient for all stages of dairy production
• Refrigerate to maintain potency — peptide drug degrades at room temperature over weeks
• Use immediately after drawing into syringe — does not survive long in plastic

Mechanism of action

Synthetic GnRH (gonadotrophin-releasing hormone) nonapeptide analogue — ~50× more potent than native GnRH and resistant to enzymatic degradation (longer half-life). Binds anterior pituitary GnRH receptors → stimulates LH (and FSH) release within 1–2 h. Peak LH at 2–4 h post-injection drives ovulation, luteinisation of unruptured follicles, and follicular cyst resolution. Standard ovsynch protocol component in dairy cattle.

Formulations and products

• Receptal VET 0.004 mg/mL (MSD, 10 / 2.5 mL)
• Gynarich 4 µg/mL (Intas, 2.5 / 5 / 10 mL)
• Pregulate Buserelin Injection (Virbac)
• Receptal VET (MSD Animal Health) — 0.0042 mg/mL (≈4 µg/mL), Injection
• Gynarich (Intas (Neovet)) — 4 µg/mL, Injection
• Pregulate (Virbac) — Buserelin acetate, Injection
• Ovulanta (Mankind Veticura) — Buserelin acetate 4 µg/mL, Injection
• Sureshot-Lin (Assure Biotech, Jagadhri (HR)) — Buserelin acetate 4.2 mcg eq. buserelin 4 mcg per mL, Injection - supplied with syringe

Storage

Injection: 2–8 °C (refrigerated) — most labels specify refrigerated. Multidose vial: 28 days after broaching (or per label). Protect from light. Do NOT freeze. May be stored at room temperature (15–25 °C) briefly during dispensing.

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

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Frequently asked questions