DHEA-S in different age groups (women)

18-29 years: 44-332 mcg/dL
30-39 years: 31-228 mcg/dL
40-49 years: 18-244 mcg/dL
50-59 years: <15-200 mcg/dL
> or =60 years: <15-157 mcg/dL

As you see, there is some individual variation, but mean DHEA values generally decline with age.

If you are supplementing DHEA on your own like many women over 35 do, please keep in mind that many drugs and hormones can affect DHEA-S levels. Drugs which are commonly used which can affect DHEA-S levels are insulin, oral contraceptives, corticosteroids, some antidepressants, metformin, and prolactin. In the case you are taking therapies for any fertility issues, I would like to say that I would never take DHEA and herbs at the same time!

Though there may not be any cross-reacting at all, the thing is that no one can tell you for sure because it has not been thoroughly tested yet (and it is difficult to test because each plant can have dozens or even hundreds of compounds which orchestrate together).

You can find more here: Why to not be reluctant to use DHEA if you are over 35 and trying to conceive.