Regumate Equine for Horses

Regumate Equine for Horses
150ml Bottle
1 litre Bottle

Images are for illustration purposes only. Packaging may change from time to time and images on our website may or may not be updated.

  • 150ml Bottle £48.99
  • 1 litre Bottle £137.99

Selection of 2 products from

£48.99 to £137.99


Regumate Equine is used to control oestrus ("heat") in mares. It is supplied as a liquid to be given directly into the mouth, or added to a small amount of food. It can be given daily to a mare early in her season and usually within 3 days it will stop that oestrus. Regumate can continue to be given once daily afterwards to prevent the return to oestrus. When daily dosing stops, 95% of mares will show signs of returning to oestrus within 5 days.

Regumate is usually used to prevent the hormone-dependant behavioural changes associated with oestrus, or to control the timing of ovulation so that the timing of mating and birth can be organised.

Please Note: A syringe is not included with these products. For a syringe to take the fluid out of the bottle please click here.

Need help or advice? Contact us:

  • Landline: 01582 842096
  • Mon - Fri: 9:00am - 5:00pm
  • Sat: 9:00am - 1:00pm
  • Email: [email protected]

All prices include VAT where applicable.

Medication Datasheets

Reviews (9)

Summary of Reviews for Regumate Equine for Horses

Overall 4
Ease Of Use
Value For Money
Absence Of Side Effects
8 out of 9 (89%) customers would recommend this product.
5 stars (5 reviews)
4 stars (3 reviews)
3 stars (1 reviews)
2 stars (0 reviews)
1 stars (0 reviews)

Only verified purchasers of this product can leave a review.

55 Regumate Equine for Horses
Verified Purchase

By on 16 June 2021

Regumate worked within 4 days to get my mare out of season and helped deal with very difficult and possibly dangerous behaviour. She was very unhappy with her own behaviour but couldn't help it. I had tried a standard non prescription medication which worked to an extent but left her still difficult.

Customer recommends this product

55 Brilliant service as usual
Verified Purchase

By on 20 March 2021


Customer recommends this product

45 Extremely effective.
Verified Purchase

By on 11 September 2020

Don't have to use it very often, but when an approaching 'season'is accompanied by exaggerated behaviour, regumate calms things down. Have also tried administering it every 3 or so, weeks to regulate behaviour, but as not all 'seasons' produce identical reactions, it's easier to keep the regumate for the occasional troublesome ones.

Customer recommends this product

55 Must have
Verified Purchase

By on 10 May 2020

Must have for my mare when in season and half the price of buying from my vet. Super speedy delivery as always from Viovet!

Customer recommends this product

35 Usually a good bet for hormone issues, but not always.
Verified Purchase

By on 13 October 2019

Historically I've had success with this product but on this occasion, it has been ineffective. I seem to have a horse in the 5% for whom this drug doesn't work.

Customer does not recommend this product

Page 1 of 2

Next Page

Q & A

Below are some recent questions we've received regarding Regumate Equine for Horses, including answers from our team.

13 July 2021 at 5:42pm

Is Regumate still effective if the bottle hasn’t been kept airtight?


Regumate was working exceptionally well for my mare. After moving to a new yard, the Regumate bottle was routinely left overnight with the syringe in the bottle with the cap not being replaced. After 4 weeks the mare has come fully into season despite continuing 12mls Regumate daily. I have now asked that the cap is securely replaced after the dose is taken from the bottle but wonder if now this has rendered the Regumate ineffective?

  • VioVet Staff

The datasheet for this product states the following:

Shelf-life after first opening the immediate packaging:
•150 ml bottle: 14 days.
•250 ml, 300 ml and 1000 ml bottles: 28 days.
Special precautions for storage
This veterinary medicinal product does not require any special storage condition.

This means leaving the cap off should not affect the expiry date. If you used the medication beyond the 14 day or 28 day expiry after opening then this may be the cause of the issue. I recommend discussing this with your prescribing vet if you have any concerns about the effectiveness of the treatment plan.

11 July 2021 at 5:46pm

Regumate on Surfaces


How long does Regumate's potency last on surfaces such as table tops, door knobs, etc.?

  • VioVet Staff

It is unknown how long this product lasts on surfaces, it is advised to wash any areas with soap/water to prevent skin contact with the medication.

27 June 2021 at 7:22pm

Regu mate


How long does this stay in system???

  • VioVet Staff

The datasheet for this product states the following:

Altrenogest is rapidly absorbed following oral administration and can be
detected in blood as soon as 10 minutes after dosing. Maximum serum
concentrations are observed 2.5 hours following administration.
Altrenogest is extensively metabolised in the liver. The terminal
half-life following oral administration is 10.7 hours ± 4.3 hours.

This means after around 4.3 hours half the medication has left the body. This means it is relatively short acting and should be out of the system within 1 day. However it's effects can last a lot longer as it alters the reproductive hormones in the horse. The datasheet states that 'these endocrine effects ensure that most mares ovulate during the four
day period between days 11 and 14 after the end of the treatment course.

13 April 2021 at 2:18pm

Regumate - expiry date

Michelle Harris

My vet has prescribed 1lt of regumate for my mare with a dosage rate of 12ml per day for 10 consecutive days. However, according to the packaging once opened the remaining Regumate should be discarded after 28 days. Does this mean I would have to throw away the remaining 880ml?

  • VioVet Staff

Yes unfortunately. The shelf life after opening the bottle and breaching the seal is 28 days for the 1 litre bottle and 14 days for the 150ml bottle. Beyond this time period it is unknown as to whether the medication is safe for future use and so should be discarded.

I recommend ordering the 150ml bottles instead if your horse only needs 120mls of the product per course. This can be done using your 1 litre bottle script if you have one, just let a member of our prescriptions team know when you upload the script to us.

3 February 2021 at 5:35pm

Regumate has frozen

Claire Melroy

  • VioVet customer since 2017
  • From: Durham, United Kingdom

If Regumate has frozen then defrosted will it still work?

  • VioVet Staff

I have contacted MSD, who manufacture this product, and unfortunately they have no data to show whetherRegumate will be safe or effective for use after freezing and defrosting. They have therefore advised discarding the product if it has been frozen and seeking a new supply.

30 December 2020 at 7:39pm

Regumate dose


We have a mare about 450 kg in weight and wonder how much her dose will be to keep her season at bay

  • VioVet Staff

This is a prescription only medication so I recommend discussing the dosage with your prescribing vet. The data sheet does have a set dose for the following indication of use though, I have pasted this below for your convenience:

[For use] In mares with significant follicular activity during the transitional
period between seasonal anoestrus and the breeding season (follicles of
at least 20-25 mm present at the beginning of treatment).

For oral administration.
0.044 mg altrenogest per kg body weight per day, for 10 consecutive days.
Carefully withdraw the volume of product corresponding to the mare
body weight (1 ml per 50 kg body weight) and administer this volume via
oral route.

27 February 2017 at 3:20pm

Can I break the prescription up to order the drugs as needed rather than all at once

Fiona Craig

  • VioVet customer since 2015
  • From: Kent, United Kingdom

My vet has given me a prescription for 2 litres of Regumate, to save me the cost of generating another script in three months. However I can't afford to buy 2 litres in one go, can I order 1 litre now and hold the prescription for you to send the second litre at the end of May? Many thanks

  • VioVet Staff

Yes that is perfectly fine. You can order one bottle now then the remaining bottle in May. Just be aware that the prescription will expire after 6 months of the issue date though and we will not be able to dispense any remaining regumate off the prescription once 6 months has passed. But you can order the medication at anytime within the 6 month window so May is fine. I hope this helps.

1 February 2015 at 11:45pm

Will this work on swine like matrix


Is this the same as matrix

  • VioVet Staff

Regumate and Matrix contain the same active ingredients, but one is marketed for horses and one for pigs.

Delivery Information