As a common health care product, there is generally no conflict and they can be used together.
Bilijian is a health care product specially developed for the elderly. The physical environment of young people is very different from that of old people, so it is not recommended.
In addition: Amway's products are mostly chemical purification products. I think there are some uncontrollable factors in the production of chemical purification products, which will have some subtle effects on the body. Therefore, it is not recommended to use such products too much for health care. The same is true of Qumei, which you mentioned later. It belongs to drug shaping products and is not suitable for long-term use.
The use of health care products should choose the right one according to your physical condition. It is not recommended to use too many health care products, but also to avoid following the trend, and try to avoid using chemically purified health care products.
After all, health care products are processed products, so it is not recommended to use them unless necessary, otherwise they will not play a health care role, but will have side effects. For example, excessive intake of vitamins may cause microbial poisoning and so on. The physical environment is a balanced system, that is to say, there must be a degree, and more and less are unbalanced. A balanced physical environment is a healthy state, and an unbalanced body may be in a sub-healthy or unhealthy state. Not everyone is in a state of balance and need of medical care.
So if you want to use it again when you need it, you can go to the hospital for a comprehensive physical examination and choose the health care products that suit you at the doctor's suggestion. Otherwise, it will not only waste money, but also be counterproductive.