The common cold is caused by viruses, most often rhinoviruses, and has no cure. This has led many to seek over-the-counter remedies that claim to reduce the duration and severity of their symptoms. Zicam has built its brand on this promise, but the efficacy of its various products depends heavily on their formulation, particularly the inclusion of zinc, and the method of delivery.
The Role of Zinc in Combating the Common Cold
Many oral Zicam products contain zinc as the active ingredient, marketed under a homeopathic label that has drawn criticism despite containing measurable zinc. Laboratory studies suggest zinc ions can interfere with the common cold virus. The proposed mechanisms include blocking rhinovirus binding to ICAM-1 receptors in nasal passages and potentially inhibiting viral replication. For these mechanisms to be effective, zinc must be administered early, ideally within 24 hours of symptom onset.
Clinical Evidence for Oral Zicam and Zinc Lozenges
Clinical trials and meta-analyses on oral zinc products like Zicam RapidMelts show potential benefits. A 2017 meta-analysis indicated high-dose zinc lozenges could shorten colds by about 33%. Other analyses support similar results for specific formulations like zinc acetate lozenges. However, effectiveness is linked to formulation and dosage (around 80-92 mg/day from acetate or gluconate via slow-dissolving lozenges) and taking the remedy at the first signs of a cold. Some reviews note inconsistencies across studies due to variations in design and dosage.
The Anosmia Controversy: Recalled Nasal Zicam
Zicam faced controversy over its former intranasal zinc-containing gels and swabs, which were recalled after the FDA issued a warning in 2009. This action followed numerous reports and lawsuits linking the products to permanent loss of smell (anosmia). The FDA received over 130 such reports. While Zicam didn't admit fault, it removed the products. The exact cause of anosmia is unclear but is thought to involve damage to olfactory sensory neurons. New, zinc-free nasal swab products were introduced, but these are homeopathic with diluted plant extracts and lack the scientific backing of oral zinc lozenges.
Comparison: Oral Zicam vs. Nasal Zicam
To clarify the difference between Zicam's various products, this table compares the oral zinc-based formulations with the older, recalled nasal products and the newer, zinc-free nasal versions.
| Feature | Oral Zinc Lozenges (e.g., RapidMelts) | Original Nasal Gel/Swabs (Recalled) | Current Nasal Swabs (Zinc-Free) |
|---|---|---|---|
| Primary Active Ingredient | Zinc gluconate/acetate | Zinc gluconate | Homeopathic plant extracts |
| Mechanism of Action | Blocks rhinovirus attachment in mouth/throat | Blocked rhinovirus attachment in nasal passages | Based on homeopathic principles (unproven) |
| Clinical Evidence | Some studies show modest benefit (shorter colds) | Some studies showed modest benefit before recall | Lacks robust scientific support |
| Primary Risk | Minor side effects (nausea, bad taste) | Permanent loss of smell (anosmia) | Very low risk of anosmia, but effectiveness is questionable |
| Consumer Feedback | Mixed reviews; some report success, others bad taste | Numerous reports of severe anosmia | Mixed reviews; less controversial |
| Status | Widely available | Recalled, no longer sold | Widely available |
The Verdict: So, Does Zicam Really Work?
The effectiveness of Zicam depends on the specific product. For oral zinc products like RapidMelts, evidence suggests taking high-dose zinc lozenges early can moderately reduce cold duration. This effect can feel significant for some, but is not guaranteed, and side effects like metallic taste are common. Current zinc-free nasal products lack strong scientific support and likely offer no more benefit than a placebo. While they are safer than the recalled versions, their ability to shorten a cold is questionable. Individual experience with Zicam is influenced by the product, timing, and potentially the placebo effect. Oral zinc has a plausible, though modest, benefit, but the history of nasal zinc controversy and the unproven nature of current homeopathic nasal sprays warrant caution.
The Final Word
Research suggests oral zinc, in specific high-dose formulations like Zicam lozenges, can shorten cold duration if used early and correctly. However, the past controversy with nasal sprays and lack of evidence for current zinc-free homeopathic nasal formulations mean consumers should be informed. Always read the label to understand ingredients and risks. A meta-analysis in BMC Primary Care offers more detail on zinc lozenges.
