Magnesium stearate is also known as stearic acid

• “Stearic Acid inhibits T-cell dependent immune responses... - Tebbey PW, Buttke TM, “Molecular Basis for the Immunosuppressive Action of Stearic Acid on T cells”, Immunogy, 1990 Jul; 379-86. 
  
   
• The Townsend Letter for Doctors and Patients, in July 1999, says that stearic acid may prevent absorption and also “might be harmful to the liver.” “...
  
   
• Cell death was induced by stearic and palmitic acid.”  PMID:  12562519 (PubMed) Ulloth, JE, Casiano CA, De Leon M., Department of Microbiology and Immunolgy, East Carolina university School of Medicine.
  
   
•  Magnesium stearate, stearic acid  and calcium stearate, made by hydrogenating cottonseed or palm oil, are used throughout the supplements industry as lubricants. They are added  to the raw materials in supplements so that production machinery will  run at maximum speeds. These fatty substances coat every particle of the nutrients, so the particles will flow rapidly. This ensures that  production schedules will meet profit targets.
  
   
• Cottonseed oil  has the highest content of pesticide residues of all commercial oils;  cotton crops are heavily sprayed. In the hydrogenation process, the oil  is subjected to high heat and pressure in the presence of a metal  catalyst for several hours, creating a hydrogenated saturated fat.  Hydrogenated vegetable fats contain altered molecules derived from fatty acids that may be toxic. The metal catalyst used in the hydrogenation  process may also contaminate the stearates produced (see Erasmus, Fats  and Oils).
  
   
• While toxicity is one problem, decreased absorption is another. In a study published in the journal Pharmaceutical  Technology, the percent dissolution for capsules after 20 minutes in  solution went from 90% without stearates to 25% with stearates (article  available from us upon request). This delays the absorption of  nutrients. Individuals with impaired digestion may have particular  difficulty absorbing nutrients coated with stearates.

Check your labels to see if you are feeding this to your horse. It’s not your fault. Many companies use this to reduce their cost.
The only way you and your horse can be safer is to educate yourself on what you’re feeding your baby.

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