Sunlight and Medicines Facts: Whenever you go to buy medicines, pharmacists advise not to keep the medicines in sunlight and try to keep them in a cool place. It is clearly written on the packets of many medicines that the medicine should be protected from sunlight and stored in darkness. The question that comes to the mind of many people is why there is a need to protect medicines from sunlight and store them in the dark? After all, what is there in medicines which is harmed by sunlight? If similar questions are roaming in your mind, then you should know the real reason for this.

The sun’s rays are full of energy. When these fall on the ingredients of the medicine, they get excited by absorbing the energy. After this photochemical reactions start. Processes such as photooxidation, photoisomerization, photodehydrogenation and photocleavage may cause the active ingredients of the drug to break down or change their structure. Sometimes new compounds are formed, which may be less effective or toxic. The effectiveness of the medicine may reduce if kept in sunlight.

Changing the color of the medicine, smell or change in transparency can be signs of spoilage. Decreased potency, especially in injectable or IV medications, can pose serious risks. Always keep medicines in their original packaging. Keep medicines away from windows, balconies or places with direct sunlight. Most medicines remain safe in a cool, dry and dark place between 15 to 30°C. If the container containing medicines is transparent, it can be wrapped in aluminum foil or a dark colored bag. Be sure to check the expiry date of the medicines and if you notice any change in color or smell, do not use the medicine.