According to http://realfarmacy.com/diy-flu-syrup/, "Elderberry Beats the Flu, Prevents Colds, and Strengthens Your Immunity." As with all dietary advice I find on the internet, I'm hesitant to believe this claim (and I'd be very surprised if the claim wasn't at least overhyped). Does Elderberry really have the claim properties?
There is limited research on the treatment of Elderberries.
However, It is officially listed as a treatment option by NCBI
Note: The presence of this link is evidence of notability rather than effectiveness.
Treatments and Therapies:
European Elder (Elderberry)
NCBI then links elderberries to the National Center for Complementary and Integrative Health
Although some preliminary research indicates that elderberry may relieve flu symptoms, the evidence is not strong enough to support its use for this purpose.
Researchers funded by the National Center for Complementary and Integrative Health (NCCIH) are studying the antioxidant effects of extracts from elderberry and their possible relevance to the body’s defense against infection.
Citation from realfarmacy.com :
Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections.
Patients received 15 ml of elderberry or placebo syrup four times a day for 5 days, and recorded their symptoms using a visual analogue scale. Symptoms were relieved on average 4 days earlier and use of rescue medication was significantly less in those receiving elderberry extract compared with placebo. Elderberry extract seems to offer an efficient, safe and cost-effective treatment for influenza. These findings need to be confirmed in a larger study.
There is not enough research to substantiate these claims.