Protocol · Immune & Respiratory
Common Cold Protocol
Zinc and Vitamin C are the core of this stack, with 2 supporting supplements. Each row gives the amount the protocol lists and the grade our evidence database holds for that supplement in Common Cold.
We are re-verifying the studies cited on protocol pages; only confirmed citations are shown.
The stack
4 supplements · 4 graded · 6 confirmed studies
| Grade | Supplement | Amount listed | Why it’s in the stack | Evidence on file | Shop |
|---|---|---|---|---|---|
| Primary stackThe core of this protocol | |||||
| Zinc | Amount listed: 75 mg daily as lozenges (within 24h of symptom onset) | Inhibits rhinovirus replication by blocking viral capsid protein binding and enhances T-cell immune function
| Grade B for Common Cold Symptoms1,377 people | ||
Confirmed studies for Zinc (titles as PubMed lists them) | |||||
| Vitamin C | Amount listed: 1–2 g daily (increase during illness) | Enhances immune cell function, increases interferon production, and provides antioxidant protection during infection
| Grade D for Upper Respiratory Tract Infection Risk5 studies · 21,620 people | ||
Confirmed studies for Vitamin C (titles as PubMed lists them) | |||||
| Supporting stackListed as additions to the core | |||||
| Elderberry | Amount listed: 600–900 mg daily during illness | Anthocyanins inhibit viral neuraminidase and hemagglutinin, blocking viral entry and replication
| Grade B for Upper Respiratory Tract Infection Symptoms3 studies · 180 people | ||
Confirmed studies for Elderberry (titles as PubMed lists them) | |||||
| Echinacea | Amount listed: 2,400 mg daily at first symptoms | Alkylamides stimulate phagocytosis and cytokine production, enhancing innate immune response to viral infection
| Grade C for CD3 Lymphocytes62 people | ||
Confirmed studies for Echinacea (titles as PubMed lists them) | |||||
Shop the evidence-backed picks
The collection holds the supplements we grade A or B for its theme, in third-party tested products where the catalog has them. It opens in our Fullscript store. You can look through it without signing in; Fullscript asks for a free account to order.
Or shop one supplement
The 2 supplements in this protocol graded A or B. Each opens third-party tested products, matched to the dose above where we can.
- Grade B
- Grade B
We earn from purchases made in our Fullscript store, and links to Fullscript, iHerb or Thorne carry our referral, so we may earn a commission at no extra cost to you. Grades come from the research and never change based on what we earn. Full disclosure
How this protocol works
In plain language
The common cold is caused by viruses (most often rhinoviruses) that infect your upper respiratory tract. Your immune system responds with inflammation, causing the familiar symptoms: runny nose, congestion, sore throat, coughing, and fatigue. While there's no cure, supporting your immune system can reduce symptom severity and duration.
- Zinc works best when taken within 24 hours of symptom onset—ideally as lozenges that dissolve slowly. It blocks the rhinovirus from attaching to cells in your nasal passages and supports T-cell function. Studies show zinc can reduce cold duration by 1-3 days.
- Vitamin C boosts immune cell activity and increases interferon production (your body's antiviral signal). Regular supplementation reduces cold severity, and higher doses during illness may speed recovery.
- Elderberry has direct antiviral effects, blocking viruses from entering and infecting cells. It reduces the duration and severity of colds and flu, especially when started within 48 hours.
- Echinacea activates your innate immune system—the first line of defense. It increases white blood cell activity and is most effective when started at the first sign of symptoms.
Expected timeline: Start zinc lozenges immediately upon symptoms (within 24h for best effect). Take elderberry and echinacea for 3-5 days. Cold duration typically reduced by 1-2 days with early intervention.