Efficacy of Lysine Hydrochloride for cold sores

In 2022, we initiated targeted compliance reviews of selected listed medicines containing Lysine Hydrochloride that made claims related to cold sores.

Why we conducted this review

Listed medicines may be subject to a compliance review at any time while they remain on the Australian Register of Therapeutic Goods (ARTG). Listed medicines are only permitted to use therapeutic claims from a pre-approved list. Sponsors of listed medicines are required to certify that they hold evidence to support their medicine’s therapeutic claims.

This review focused on verifying whether sponsors had appropriate evidence to support their cold sore-related claims.

What we reviewed

We selected ten (10) listed medicines containing Lysine Hydrochloride, that made one or more of the following claims:

• Decrease/reduce/relieve burning/tingling associated with facial cold sores
• Decrease/reduce/relieve symptoms of facial cold sores
• Enhance/improve/promote healing of facial cold sores
• Helps reduce occurrence of facial cold sores

The medicines were either selected randomly or based on regulatory intelligence.

What we did

We asked the sponsors of these medicines to provide evidence to support their claims. Our assessment focused on:

• the relevance of the evidence to the specific medicine; and
• the quality of the evidence provided.

This process helped us determine whether the sponsors’ certifications were accurate and whether the claims made were compliant with regulatory requirements.

What we found

The sponsors of all (10) targeted medicines (100%) responded to our request for information. However, the evidence provided was not sufficient to support the cold sore-related claims made for any of the medicines.

Sponsors of all medicines (100%) made corrective actions to remove the unsupported cold sore-related claims from their medicines and their advertisements.

The following are some examples of the common issues identified in the evidence provided:

• Low study quality
  • Some studies lacked proper placebo or control groups, had too few participants, or failed to report key data needed to support their conclusions.
• Inconsistent dosage
  • The dosage used in the studies sometimes did not match the dosage of the medicine under review.
• Lack of relevance
  • In some cases, studies involved different population groups, routes of administration, or active ingredients that did not align with the medicine being reviewed.

The compliance review results for each medicine reviewed are published on the page Listed medicine compliance reports. Search for ‘cold sore management’ in the search bar.

Information for sponsors

If you are the sponsor of a listed medicine containing Lysine Hydrochloride that make claims related to the management of cold sores, you should:

• review your evidence in accordance with the Evidence Guidelines for listed medicines; and
• re-evaluate the presentation of the medicine (including the name, label, web advertising, and its ARTG entry) to ensure that all claims made, especially in relation to cold sores, are accurate, truthful and not misleading.

Please be aware that your medicine may be selected for review at any time. We strongly encourage proactive sponsor engagement to ensure that your medicine complies with all relevant legal requirements at all times. Repeatedly failing to comply with legislative requirements could result in escalated enforcement actions, including infringement notices or other penalties.