Hyaluronic acid and its risks - Restylane, Juvéderm, Surgiderm, Teosyal, Matridex, Matridur (hyaluric acid derivates) - Forums & Discussion 

HA exists in many human body\'s system organs, therefore rejection or hypersensitive reaction possibility are very rare, unless the used HA is badly manufactured or stored. in literature its mentioned that some thin sized molecule HA might cause localized fibrosis, Its also reported that HA rarely may cause allergic reactions. There is no enough data about administration by mouth (Orally). Its reported that HA rarely can cause little pain and redness at the injection site (during our decade of practice we never faced any of the above mentioned side effects), meantime such a side effects are temporally and usually subsides within minutes or hours. Because we don\'t know if it passes to the breast milk, or cross the placenta of the pregnant, we postpone its use in such cases. Finally, the more experienced the practitioner is, and the use of well known purified HA products, both of these cautions decreases the possibility of any potential side effects to be faced. Therefor, Hyaluronic acid (HA) injection is relatively safe for most people.

Hyaluronic acid (HA)injection is safe for most people. There is no enough data about administration by mouth (Orally).
Its reported that HA rarely can cause little pain and redness at the injection site (during our decade of practice we never faced any of the above mentioned side effects), meantime such a side effects are temporally and usually subsides within minutes or hours. Its reported that HA rarely may cause allergic reactions.
Because we don't know if it passes to the breast milk, or cross the placenta of the pregnant, we postpone its use.

Finally, the more experienced the practitioner is, and the use of well known purified HA products, both of these cautions decreases the possibility of any potential side effects to be faced.