Woad
An ancient Chinese antiviral herb (Ban Lan Gen) used for centuries against infections and fevers. Evidence is mixed, so set expectations accordingly.
🏆
Verdict
5/10 Mixed
🎓
Evidence
Grade B / 100+ Studies
Antiviral properties (traditional and preclinical)Anti-inflammatoryTraditional fever and infection support
Norans Kepals, Independent Researcher & Supplement Expert
March 1, 2026
The No-BS Summary
8 things. 60 seconds. Everything you need.
1
2
3
4
5
6
7
8
⚡
1
WHAT IT DOES
An ancient Chinese antiviral herb (Ban Lan Gen) used for centuries against infections and fevers.
🏆
2
DOES IT WORK?
Results vary. Isatis tinctoria/indigotica root (Ban Lan Gen) is one of the most famous antiviral herbs in TCM. Used extensively during SARS and flu outbreaks in China. Contains indirubin and other alkaloids with demonstrated antiviral and anti-inflammatory properties in lab studies. Limited Western clinical trials, but deep traditional use and plausible mechanisms.
💊
3
HOW MUCH TO TAKE
500-1500 mg root extract or 9-15 g dried root in decoction
💰
4
COST
Budget-friendly. $20-35/month for quality brands.
⏱️
5
FIRST 24 HOURS
Don't expect miracles on day one. It's building in your system.
📈
6
AFTER A FEW WEEKS
Most people notice something by week 2-3.
🛡️
7
SAFETY
Few things to check: limited western clinical evidence, may cause nausea or diarrhea at high doses. Worth mentioning to your doc.
✨
8
HOW IT FEELS
Effects vary person to person. Give it time.
2The Breakdown
Quick Answers
Dose-Response Curve
How effective is woad at different doses? Here's what the research shows.
Effectiveness %
0
25
50
75
100
MIN 500mg
SWEET SPOT 1.0g
PLATEAU 3.0g
Dose (mg)
0-54%
Sub-therapeutic
<500mg
54-82%
Effective
500mg-1.0g
~82%
Optimal
1.0g
82%
Diminishing
>3.0g
Moderate confidenceBased on clinical data + estimates
Source: Chinese Pharmacopoeia; Ye & Zhang, 2011Bottom line: Most research uses 1.0g daily. Below 500mg, you're probably wasting money. Above 3.0g, you're not getting extra benefit.
Dosing Guide
When
As directed
How
500-1500 mg root extract or 9-15 g dried root in decoction
Food
With or without food
Onset & Feel
Builds Over Time
Effects vary
Effects vary person to person. Give it time.
Cycle
As needed
How to Take It
Woad comes in several formats. Pick what fits your lifestyle.
Capsules/Tablets
Pre-measured doses, easy to take.
✓ Convenient✓ No taste✓ Portable✗ More expensive✗ May need multiple
Powder
Mix with water or a shake.
✓ Cheapest✓ Flexible dosing✗ Needs mixing✗ Taste varies
Softgels
Oil-based for fat-soluble nutrients.
✓ Better absorption for fats✓ No taste✗ Larger pills
Pick this:
Capsules for convenience, powder for value.
Skip this:
Check for unnecessary fillers and additives.
Delivery affects convenience and cost, not usually effectiveness.
Did you know?
Many studies and counting.
Heads Up
Generally safe at recommended doses. Talk to your doc if you have concerns. Check with your doc if: Limited Western clinical evidence, May cause nausea or diarrhea at high doses, Not a substitute for antiviral medications.
3Deep Dive
The Science, Simplified
For those who want the full picture
Woad has emerging evidence.
Trust Signals
Grade B
Evidence
50+
Studies
30
Human Trials
0
Meta-analyses
👍 Strong evidence. Most claims hold up under scrutiny.
Mechanism of Action
Indirubin and indigo alkaloids inhibit viral replication and modulate immune response. Epigoitrin has shown antiviral activity against influenza in vitro. Root polysaccharides stimulate macrophage activity and enhance innate immune response.
Research Summary
Scientific consensus: undefined/10.
Consensus: /10LIMITED Evidence
Origins & Manufacturing
Where does woad come from? Let's get nerdy.
How It's Made
Manufacturing process varies by supplier.
What to Look For
✓ Third-party tested✓ GMP certified
Drug & Supplement Interactions
4For You
Is Woad right for YOU?
Get a personalized verdict based on your health profile.
Products with Woad
Supplements that contain this ingredient
Medical Disclaimer
This content is for informational purposes only and is not intended as medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any supplement regimen, especially if you have medical conditions or take medications. ARE Supplements does not endorse any specific products.