Question

we should avoid taking medicines/drugs unless prescribed by a doctor.why?

Answer 1

There are several reasons why taking unpescribed medication is wrong:
1) Medicines/drugs have several adverse effects 
Many times people take medications because the health benefit outweighs the side effects that the drugs have. However, when you take medications that are not meant for you, you might just end developing the side effects without any health benefits from the drugs.
2) Different people react to different medications in different ways. When you take medication that is not meant for you, you might develop reactions that might harm your health. Your doctor is able to advice you o which medications to take incase he/she finds out that you are allergic to certain compounds in that drug.
3)Prescribed medicines come with right amount of dosage that one should take. When you take medications not prescribed to you, you might end up overdosing, poisoning your self which may leave you with a severe health problem like damaged liver or worse(one might end up even dying from the toxicity.

Answer 2

Answer

Adolescent is a period of much activity in the body and mind, which is normal part of growing . so do not feel insecure if anybody suggest you will get relief if you take some .just say

'No' unless prescribed by doctor.

drugs are addictive if you take them once you feel like taking them again and again they have the body in the long run they ruin health and happiness.