The doctor has recommended to me for strengthening immunity of a drop "Derinat". Tell or say...

[Nastja]

The doctor has recommended to me for strengthening immunity of a drop "Derinat". Tell or say, they really help or assist?

[Horoshilova N.V.]

I can not tell or say, t. To. Anything about you I do not know.
All depends on a concrete situation. Conditionally speaking Petrov - help or assist, and to Sidorov - is not present.