My reference manual list these herbs to avoid while taking Zoloft, but I would definitely check with my doctor before taking ANY "natural" herbal or supplement.
These herbs are:
ephedra
St. John's wort
SAM-e
corkwood
jimsonweed
hops
lavender
No mention of Grapeseed........but bear in mind that it was only recently discovered that taking Xanax and grapefruit was not recommended. Please check with your doctor or a pharmacist.
Peace
Greenlydia