Regumate Equine for Horses

Regumate Equine for Horses
1 litre Bottle
150ml Bottle

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  • 1 litre Bottle £142.99
  • 150ml Bottle £48.99

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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.

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All prices include VAT where applicable.

Medication Datasheets

Reviews (18)

Summary of Reviews for Regumate Equine for Horses

Overall 4
Ease Of Use
Value For Money
Absence Of Side Effects
17 out of 18 (94%) customers would recommend this product.
5 stars (8 reviews)
4 stars (8 reviews)
3 stars (2 reviews)
2 stars (0 reviews)
1 stars (0 reviews)

Only verified purchasers of this product can leave a review.

55 Fantastic product
Verified Purchase

By on 26 July 2023

This product keeps my mare being a normal horse instead of a fire breathing dragon.

Customer recommends this product

45 Regulated her moods
Verified Purchase

By on 26 July 2023

Used for 6 months & has helped her be a happier horse, no big up & downs now. She still calls & squeals but alot more tolerant of geldings.
I can now ride more frequently without the worry of her moods…

Customer recommends this product

55 Regumate
Verified Purchase

By on 20 July 2023

Great product for hormonal mares 👌

Customer recommends this product

45 Regumate
Verified Purchase

By on 16 May 2023

Have used previously for our female zebra

Customer recommends this product

45 Calming effect
Verified Purchase

By on 6 February 2023

Only started it 2 weeks ago but already she is more relaxed & happier than previously.
Always had painful seasons but after moving to a larger yard with more geldings she was constantly in season. Her last season being particularly stressful, constantly calling, pacing & bad tempered, so our last resort but has definitely helped.
Only negative is the larger bottle does not come with a screw in syringe so need to purchase separately.

Customer recommends this product

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Q & A

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

21 February 2023 at 11:10am

Prescription medication

Michelle Wright

Hi, I’m looking at getting a prescription from my vet for my mare, if I order regumate through viovet how long will it take to receive it?

Regards Michelle

  • VioVet Staff

Estimated delivery dates and options are provided during our checkout process. Please head online to place your order. These will be provided before any payment is taken.

14 November 2022 at 4:14pm

When do you start this in the mares cycle


When do you start this in the mares cycle? The instructions don’t actually say. My mare is currently in season. My impression from vet was ok to start now, but a 150ml bottle only does 12 days so just wanted to make sure?

  • VioVet Staff

The datasheet for this medication states the following regarding it's 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).

It is advised to contact your vet so they can recommend when to start in line with the above information.

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.

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