>How is semen produced in the body?
The human body works in layers of fundamental "element components". These layers describe how and what the body is made up of at a high level.
All the layers are not just interconnected but also cyclical in nature.
The seven key layers in the body, in sequence, are:
>1. Consumption of food/juices
>2. Blood
>3. Muscles
>4. Fat
>5. Bone
>6. Bone Marrow
>7. Semen
>8. Ojas (or "The Light")

After food is consumed, each physical layer takes about five days to transfer to the next layer (i.e. from digestive system to blood, then muscles, etc) totalling to about 35 days until the 8th layer.

Each of the layers supports each other and has its defined "job" to do in the body.
Semen is like the horse-power of the body. Once semen is developed, Ojus comes into being. Ojus can protect against all forms of negative energies and diseases.

After every about 35-40 days this cycles helps make better of everything at every step (i.e. better digestion of consumed food, better blood, ect. Until powerful Ojas (meaning each day it creates certain amount of energy from the food consumed 40 days earlier to that day.)

Unless this cycle is broken (from semen ejaculation) everything keeps improving continuously.
So essentially once semen is ejaculated, it weakens all the above steps in the entire cycle, until semen is regenerated back properly, which takes its own time.