Starts off to test frog, given dash of hormone (9)

I believe the answer is:

oestrogen

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'dash of hormone' is the definition.
'oestrogen' can be an answer for 'hormone' (I've seen this before). I'm unsure of the 'dash of' bit.

'starts off to test frog' is the wordplay.
'starts' says to take the initial letters.
'to test frog' becomes 'estrogen' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
The first letter of 'off' is 'o'.
'o'+'estrogen'='OESTROGEN'

'given' is the link.

Can you help me to learn more?

(Another definition for oestrogen that I've seen is " Hormone".)

I've seen this clue in the Sydney Morning Herald.

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