side effects biotin 5000
1 Allergic Reaction: This is one of the side effects of taking Biotin 5000 Mcg, especially for people with extremely sensitive skin. 2  They can experience skin eruptions at any part of the body and even itchiness or rashes.3  Chest and throat tightening are also reported side effects with people suffering from cobalt allergy.or instance, in the case of Biotin deficiency in kids, it is generally advised to have around 10 to 20 Mcg of Biotin. Biotin 5000 Mcg Side Effects. Even though Biotin 5000 Mcg is supposed to be an ideal dosage of Biotin, this may even result in certain side effects to several people.