I have been a customer of Higher Nature for many years.If my memory serves me correctly,the Optimum nutritionist,Patrick Holford supported their products as did an elderly doctor/nutritionist,sorry his name escapes me,whose clinic I attended many years ago.They also were instrumental in promoting colloidal silver which I believe was researched and then made available in the public domain by one of their own nutritionists.I only gave a 4 star rating this time as I was unable to buy the effervescent magnesium tablets normally available which provide not only a refreshing drink but give my adrenals instant support when needed.