Progressive Earth Christmas Opening Times

Last shipping in 2021 will be on 21st December. Please order your supplies soon to avoid running out in the busy period before and after the festive holidays. Click here for full details.

To Support a Healthy Hindgut and Maintain a Healthy Immune System for Horses.

MAGNESIUM OXIDE 99.7% to 99.8%. Ultra low iron content. Mineral for forage balancing, strong hooves and laminae connection, Equine calmer, metabolic health.



Magnesium Oxide, actual purity 99.7% to 99.8% MgO.

Please note the actual percentage of Magnesium Oxide MgO varies between 99.7% and 99.8% depending on the batch number of the product in stock. The actual percentage will be written clearly on the bag.

Magnesium Oxide 99.7% to 99.8% is a high purity ultra low iron pharmaceutical grade magnesium. It is virtually tasteless, making it well accepted in food.
It is a very fine particle size for optimum absorption.

  • Magnesium oxide is the primary ingredient in many of the quality equine calming products on the market.
  • Magnesium is needed for more than 325 enzymes within the horses body.
  • Involved in protein synthesis so needed for general growth and repair of tissue, e.g. Hooves.
    Required for the maintenance of normal blood circulation within the body, limbs and feet of the horse
  • Magnesium is critical for balanced secretion of insulin and glucose uptake.
  • It is involved in supporting correct blood sugar levels after carbohydrate intake and inadequate levels are
    associated with incorrect insulin function  (symptoms include cresty neck and/or fat deposits).
  • Magnesium is essential for proper calcium absorption and is an important mineral in the bone matrix.
    It can also assist in the absorption and metabolism of Vitamins B, C and E.
  • Low levels of Magnesium can result in nervousness and an inability to concentrate, tight tense muscles
    which are less able to relax, tightness or tenderness through the back, slow to warm up.
  • Periods of stress lead to an increased need for magnesium.
  • Magnesium is often lacking in equine diets due to processed, preserved, high concentrated feeds.
  • Magnesium is important for the detoxification of toxic substances from the body. It supports
    against heavy metal toxicity.
  • The availability of magnesium is low in; fast growing lush grass; after periods of rainfall; in
    acid soils i.e. ‘horse sick pastures’ or artificially fertilised pastures (acid conditions destroy soil
    microorganisms which are used to make the minerals usable by plants).
  • Useful when magnesium needs boosting in the diet of horse and ponies prone to laminitis.

Feeding guidelines (Requirement may vary):

2g of Magnesium Oxide 99.7% to 99.8% per 100kg of bodyweight,  (10g of magnesium oxide daily for an average 500kg horse)

1 X 15ml measuring scoop = 10g Magnesium Oxide 99.7% to 99.8% (providing approximately 6g elemental magnesium)
1 X 25ml measuring scoop = 15g Magnesium Oxide 99.7% to 99.8% (providing approximately 9g elemental magnesium)


Pack size and availability: Progressive Earth Magnesium Oxide 99.7% to 99.8% equine feed supplement is available in resealable grip seal pouches containing either 1 Kg, 2 Kg or 4 Kg of product (Scoop not include).
Multiple purchase options are available.

43 reviews for MAGNESIUM OXIDE 99.7% to 99.8%. Ultra low iron content. Mineral for forage balancing, strong hooves and laminae connection, Equine calmer, metabolic health.

  1. Claudia M.

    My two year old is much more calm and his hooves have improved. Thank you

  2. Lesley Southam

    Excellent service. Great product

  3. Sue Dymond

    All good

  4. Deborah

    Quality product — never lumpy.

  5. Emma

    This product is the best quality and most cost effective I have found. Progressive Earth products are always accepted by my horses straight away (I have had trouble with other companies products in the past – even when introducing slowly). Great products and company

  6. Lesley McDowell

    Very quick delivery

  7. Bruce Botrel


  8. Anonymous

    I was looking for a supplement that would help my mare’s mood and her hooves. My mare can be a bit stroppy, so started using this product as an addition to her feed. So far she appears to be a lot calmer and hooves are looking good.

  9. Anonymous

    Works well

  10. Lesley McDowell

    Very good quick service

  11. Karen M.

    Always prompt and as described

  12. Di P.

    Trusted product

  13. Amanda

    Well packaged

  14. Eveline Guarino

    Very pleased with result on my 8 horses

  15. Anonymous

    Works really & and excellent service

  16. Anonymous

    Good quality and quick delivery

  17. Anonymous

    Progressive Earth is a great company. They are fast to ship, have great customer service and great products that are suitable for my sensitive EMS horse. I love the little chocolate bar you get in your package too! Thank you Progressive Earth 🙂

  18. Wendy

    Excellent quality. Even better service.

  19. Kate B.

    My horse eats this MgO happily and needs less than the previous product I used, so it’s more cost effective as the same weight of product goes much further

  20. Anonymous

    Good product, quick delivery

  21. Anonymous

    Super company, very responsive, quick deliveries!

  22. Sam C.

    Excellent product – has transformed my spooky mare

  23. Ella Livingstone

    Good price for high purity product. It is a VERY fine powder though so can be challenging to work with!

  24. Zoe

    Excellent product ! It actually works much better than any other brand I’ve used over the past 20 years !

  25. Anna

    Prompt efficient service and helpful knowledeable advice

  26. Erika Alexander

    Very good product which comes in foil bags not plastic which helps the environment

  27. Penny R.

    Great product!!

  28. Katherine Arthur

    High quality and purity at a low price!

  29. Lydia

    Brilliant for adding magnesium alone to the diet. I did lots of comparison of magnesium supplements before going for this due to the superior composition. Great products from Pro Earth as always!

  30. Maria

    Good quality, taste seems to be a bit of a problem but I guess that can’t be helped, so difficult to get the quantities in that I want, especially with ponies that haven’t got big feeds

  31. Ian B.

    Excellent quality and packaged well for storage once opened.

  32. Gillian

    palatable and horses have not been footy this year

  33. Kay Puddle

    Product as described. Fast delivery. Thank you

  34. Victoria M.

    Great service and product

  35. Anonymous

    Easy to order, quick delivery

  36. Ian Harrison

    Good product and quick service

  37. Kelly

    Excellent product excellent service

  38. Katherine Arthur

    High purity magnesium at a great price.

  39. Hazel M.

    Like all their products great quality and good price.



  41. Adele Hughes-jones

    Perfect as always

  42. Michael C.

    High quality product at a great price

  43. Susanne Britton Hickson

    My barefoot, spooky Warmblood does very well on this, in addition to his Pro mineral mix. At 650kg I only add about half the recommended daily dose to boost the mineral mix. He’s sane and sensible on that and his feet are extremely strong. Well worth the money.

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