Can both "by" be omitted?

I can see how the first "by" can be dropped out but not the second.

In my opinion both instances of 'by' can be omitted without affecting the meaning.

For what it’s worth I agree with Tsar

The preposition 'by' to indicating a means can usually be omitted before the word 'using'.

Turn the screw by using a screwdriver.
Turn the screw using a screwdriver.
I paid my hotel bill by using my credit card.
I paid my hotel bill using my credit card.

Also in other situations:
I avoided the guards by moving only when they weren't looking.
I avoided the guards, moving only when they weren't looking.

I do not see why a distinction is being made by some people between the first 'by' and the second. Each performs the same task which is duplicated by the word 'using'. If the first can be dispensed with, why not the second? In the name of consistency of style, either both should stay, or both should go.

conceive [by] using drug A
inhibit FSH [by] using drug E

They are harmless operatives. Using them doesn't distort the meaning, dropping one or both neither improves the writing nor makes it more difficult to understand.

I vote to leave them as they are.

Joe( by the by)Nation

Because omitting “by” makes it seem that the FSH is doing the using

No it doesn't.

Thank you guys.
If not used "inhibiting", can we use "the inhibition of" instead?

yes. but don't.