So, usually you're in a doctor's office

所以通常你得在医生办公室
or a hospital,

或者医院接受注射
you don't do it yourself at home.

你不能在家自助完成
There is a risk

否则会有风险
because you're introducing drugs at high concentration into the blood.

因为你将高浓度的药物引入血液中
There's much more risk of overdose or toxicity

服药过量及药物中毒的风险比较高
because the concentration's going to change very rapidly.

因为药物浓度变化的非常快
Even though you might know what the average response to a drug is,

即使你知道药物产生效应的平均时间
average among a population of people,

它是一个人群内的平均时间
we're all different in ways that are important to how drugs act.

而药物在每个人身上的作用方式都不一样
You know this, if you take Ibuprofen,

你知道如果你服用布洛芬
you read the dosage on the label,

阅读标签上的使用剂量说明