herb · for frequent colds
Elderberry
Appears to help your immune system react faster, and makes it harder for the virus to get into your cells.
Say that in clinical terms
Anthocyanins stimulate cytokine production and inhibit viral neuraminidase, preventing viral entry into host cells.
How strong is the research?
3 papers read, 3 supporting.
Who was studied: Studied in adults with confirmed or suspected flu and colds. A fair match if you actually have one.
How much to take
daily
300–600 mg
Start at first symptoms. Standardized to anthocyanins. Safe for acute use.
Before you take it
- Raw and unripe elderberries (Sambucus nigra) contain sambunigrin, a cyanogenic glycoside that can cause nausea, vomiting, and diarrhea; commercial standardized extracts are processed (heated or membrane-filtered) to eliminate this compound.
- Immunostimulant activity is documented; theoretical risk of exacerbating autoimmune conditions and antagonizing immunosuppressant drugs (cyclosporine, tacrolimus, corticosteroids); at least one case report of autoimmune hepatitis temporally associated with elderberry use.
- In vitro studies show weak inhibition of CYP1A2, CYP2D6, and CYP3A4; a second in vitro study found no inhibitory effect on these enzymes; no clinically significant pharmacokinetic drug interaction in humans has been confirmed, but precaution is appropriate with narrow-therapeutic-index CYP3A4 and CYP2D6 substrates.
- No NIH/IOM Tolerable Upper Intake Level (UL) has been established for elderberry extract; it is an herbal botanical without a defined supplemental intake ceiling analogous to micronutrient ULs.
- Insufficient safety data exist for use during pregnancy or lactation; the European Medicines Agency recommends against use in these populations due to absence of adequate evidence.
What we make of it
Four of the five trials were funded by the people selling it, and the study we cite cannot be found.
The detail
Three problems stack up here. The paper we cite cannot be located at all. The closest real review is not a pooled analysis, so calling it one overstates how solid the evidence is. And that review found four of its five trials were manufacturer-funded and rated the certainty of every result as low or very low. The idea that elderberry blocks the virus from entering cells comes from laboratory work, not from people.