In terms of adverse effects, aloe gel is used in research experiments more often, and is generally regarded as safe with minimal side effects. In some rare cases, aloe has been found to cause allergic reactions when applied topically (Klein & Penneys, 1988). On the other hand, caution must be taken when administering aloe orally. Aloe latex as a laxative can cause diarrhea, abdominal pain and heart disturbances (Haller, 1990). It can be fatal if taken in large doses over several days. Also, as a laxative it may decrease the efficacy of other oral drugs. Aloe may lower blood sugar, so combined effects with other medications that also lower blood sugar such as antidiabetic drugs may be harmful. Aloe may also decrease blood clotting and increase the chances of bleeding, so it is advised to be cautious if blood thinners are being taken or before a surgical procedure. In regards to other herbs, as aloe is a laxative and when used with other herbs such as black root, jalap root and rhubarb root that also have laxative properties may be harmful. Also, herbs such as horsetail, liquorice and figwort that lower blood sugar levels in combination with aloe may be unsafe (MedlinePlus, 2010).
