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For improved joining performance and increased ovulation rates in sheep

Regulin Implant SDS (Aug2021).pdf


Get up to 20% more lambs with Regulin®


Each implant contains 18 mg melatonin


As the days get shorter and nights longer during autumn, ewes and rams naturally come into their peak productive performance. But the longer days of spring/summer are less productive than autumn joinings because there's reduced fertility and lower lambing rates due to a lower melatonin level in the animal.

Regulin moves the reproductive peak of autumn to the spring. A small implant releases melatonin - nature's day length messenger - to 'trick' the animal’s reproductive system into thinking the days are shorter than they really are, triggering the natural sequence of hormonal events and an increase in reproduction.


Regulin offers many benefits for producers, including:

  • Fully maximise the genetic potential of your sheep
  • Reduce joining times - compress lambing periods
  • Reach the full potential of your rams - year round
  • Maximise your genetic gains
  • Ideally suited to all enterprises, stud, wool and prime lamb producers
  • Increased fertility in early joining
  • More productivity and income per ewe mated
  • Earlier to market and less trucking of lambs

Use by subcutaneous implantation only.
Administer one implant to each ewe three implants per ram 40 Days before joining rams with the ewes.
Use the Regulin implanter to place one implant beneath the skin (subcutaneously) near the base of the ear. For rams implant the three implants in the same place be pulling the trigger three times.

Precautions and contraindications:

  • Contraindicated for use in reproductively immature animals or pregnant animals
  • It is contraindicated to treat ewes that are to be joined in Autumn that cannot be joined in 30-40 days from treatment.
  • Sterilise needles by boiling before use. Avoid the use of strong disinfectants. Keep needles sharp and clean; replace frequently.
  • Maintain cleanliness at all times.

Regulin is recommended for use in Merinos and First Crosses joined in Spring and early Summer (October, November, December, January and Febuary) for lambing in Autumn. 

Use of Regulin is not recommended earlier than September. Check with Ceva technical staff should you have this requirement. 

Regulin treatment is also effective in British breed ewes such as Border Leicester, Romney and others. However, the treatment timeings may differ from that above.

Producers contemplating use of Regulin in British breeds should seek advice from Ceva Animal Health.

Use by Subcutaneous implantation only. Use the Regulin implanter to place implant beneath the skin (subcutaneously) near the base of the ear (see Figure below).

Regulin implanter


Implant the animals 40 days prior to the selected joining date. Regulin provides the maximum productive returns when used 40 days prior to ram introduction, for other timings and other protocols contact Ceva Animal Health.


In order to maximise results from Regulin treated ewes, it is essential that rams are isolated from the ewes for at least 42 days prior to joining. Effective isolation usually involves maintaining rams in a non-adjacent paddock to the ewe flock. Out of sight, sound and smelling range of the ewes.


Regulin advances the seasonal peak of ovarian activity, it does not overcome seasonality altogether. As different species and breeds have different breeding patterns, the recommended period for use varies.


Use only in reproductively mature ewe lambs, maiden and older ewes.
Regulin will not replace good husbandry practices in achieving good reproductive performance – for good results, animals must be in healthy condition.


Sheep are seasonal breeders. Their reproductive performance varies throughout the year, reaching a peak in Autumn. Treatment with Regulin will induce an earlier peak in joining performance and ovulation rate.
Treatment enables earlier joining of very seasonal breeds of sheep.
In less seasonal breeds of sheep it also concentrates lambing and increases the percentage of lambs born (without increasing the number of triplets or quadruplets).
Melatonin, the active ingredient of Regulin, is a substance naturally produced by all animals. Regulin implants give a controlled delivery of melatonin over an extended period. The implants are non-toxic and completely bio compatible.


2 x 25 implants


Store below 30°C (Room Temperature).


For General Sale (APVMA 38233)



Milk: NIL

FIRST AID: If poisoning occurs contact a doctor or Poisons Information Centre, Phone Australia 131126.

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