Questions and Answers: Regulation of Medicinal Maggots / Medicinal Leeches

What are medicinal maggots?

Medicinal maggots are fly larvae that are specially prepared for human therapeutic purposes. The use of medicinal maggots is sometimes referred to as "Maggot Debridement Therapy", "Larval Therapy", or "Biosurgery". Certain species of maggots (i.e. Lucilia sericata or Phaenicia sericata) have been used as an alternative to surgery to treat non-healing and infected wounds. They secrete an enzyme in order to digest necrotic tissue.

What are medicinal leeches?

Medicinal leeches are fresh water annelids that are specially prepared for human therapeutic purposes. The use of medicinal leeches is sometimes referred to as "Hirudotherapy".  Certain species of leeches (i.e. Hirudo medicinalis) have been used by surgeons after re-attachment surgery (such as finger re-attachment) and applied to healing graft tissues to help blood flow. To do so, they secrete hirudin, which is a powerful anticoagulant.

Are medicinal maggots and leeches different from maggots and leeches found in a natural setting?

It is important to distinguish between medicinal maggots and leeches from those found in nature. Medicinal maggots and medicinal leeches must be raised in a closely controlled environment under Good Manufacturing Practices, and companies that raise leeches or maggots for therapeutic purposes must use various techniques to process them before distributing them for therapeutic purposes.

Are medicinal maggots and leeches regulated by Health Canada?

Medicinal maggots and medicinal leeches are regulated by Health Canada as drugs under the Food and Drugs Act and Regulations.  Both are considered to be "drugs" because they secrete a substance that is used for a therapeutic benefit and therefore meet that definition under the Food and Drug Act.  Medicinal maggot and medicinal leech sponsors must comply with Part C of the Food and Drug Regulations.  The applicable regulatory requirements are listed in Divisions  1,  1A,  2,  5, and  8 of the Food and Drug Regulations.

The Food and Drug Regulations require anyone intending to sell or distribute these products in Canada to obtain market authorization. The Biologics and Genetic Therapies Directorate (BGTD) is the section of Health Canada that is responsible for the regulatory oversight of these products. Sponsors are encouraged to set up a pre-submission meeting with BGTD to discuss regulatory requirements for obtaining a market authorization medicinal maggots or medicinal leeches.

In the absence of a market authorization, access to medicinal maggots and medicinal leeches can only be obtained via a clinical trial which has been authorized by Health Canada, or via the Special Access Programme which allows practitioners to obtain access to unauthorized products to meet an individual patient's needs.

Why are medicinal maggots and leeches being regulated now?

Medicinal maggots and leeches have been used throughout history for various therapeutic purposes. More recently they are being manufactured differently (for example, by using propriety solutions to wash the product) and distributed with specific health claims. This triggers the Food and Drug Regulations and requires evidence to support health claims.

Are medicinal maggots and leeches regulated in other international jurisdictions?

Medicinal maggots and leeches require regulatory authorization for use in other international jurisdictions. For example, medicinal maggots and leeches require authorization from the European Medicines Association in the European Union and the Food and Drug Administration in the United States.

What is the intent of a clinical trial?

The intent of a clinical trial is to research and gather information on a drug's dose, effectiveness and safety in humans. Trials are undertaken with informed and consenting human subjects according to good clinical practices. This provides a controlled environment where the procedures for drug administration and the evaluation of the results are closely monitored. Data captured can subsequently be used to support market authorization.

Prior to the commencement of a clinical trial for medicinal maggots or leeches, in Canada, BGTD will review information submitted in a Clinical Trial Application. This application requests permission to distribute the drug to responsible clinical investigators that are named in the application. Some of the information contained in a clinical trial application includes the results from preclinical tests, production methods, dosage form and information regarding the investigators who will be Practitioners and distributers are encouraged to obtain clinical trial authorization so that these products are available to patients, and conducting the study.

For more information about conducting clinical trials in Canada, please refer to the Clinical Trials Manual.

What information will be required to obtain market authorisation?

The onus is on the sponsor to provide evidence that their product is safe, of good quality, and effective. This requires the filing of a New Drug Submission, containing an acceptable combination of manufacturing and clinical information, which may include the following:

Manufacturing (Quality)


  • design of the product manufacturing facility
  • cleaning and sanitization procedures for manufacturing equipment
  • description of how the facility provides an adequately controlled environment

Process/Product Description

  • a comprehensive list of all components used in the preparation of the medicinal maggot or medicinal leech
  • a description of the species of maggot or leech used
  • a description of the method for confirming the species used
  • a complete description of the manufacturing process and controls employed during the growth of maggots or leeches, including leech or maggot feed
  • validated acceptance criteria for the final product


  • details regarding the stability of the product in its packaging over a period of time, which has been used to determine its shelf life (as applicable)
  • a complete description of the container closure system and packaging including the labelling
  • a justification for how the container closure system and packaging is adequate and appropriate for safe and effective use


An acceptable combination of the following:

  • a description and summary of findings from clinical trials carried out by the sponsor under the conditions of use proposed, which provides evidence that the benefits outweigh the risks (i.e. that the product is safe and effective)

  • a description and summary of case studies using the product under the conditions of use proposed
  • an acceptable combination of the above PLUS reliable information regarding the use of medicinal maggots and medicinal leeches, which may include the following
  • peer reviewed information describing the safe and effective use of the product
  • information describing any related evidence of a history of safe and effective post‑market ("real world") use either in Canada or elsewhere

What is the Special Access Program, and how can I apply for access?

The Special Access Programme considers requests from practitioners for access to non‑marketed drugs for treatment of life‑threatening conditions when conventional therapies have been considered and ruled out, have failed, are unsuitable, and/or unavailable.  The regulatory authority supporting the programme is discretionary and a decision to authorize or deny a request is made on a case‑by‑case basis, by taking into consideration the nature of the medical emergency, the availability of marketed alternatives, and the information provided in support of the request regarding the use, safety and efficacy of the product.

Practitioners are encouraged to contact Health Canada's Special Access Programme (SAP) as soon as the need for leech therapy is identified. The SAP operates 24 hours a day 365 days a year. Completed requests may be faxed at any time, but given the nature of the circumstances in which leeches are often required practitioners are encouraged to call 613 941‑2108 to confirm receipt. Please consult the SAP section of the Health Canada website for more information on access request forms.

Can I import medicinal maggots and leeches for use without regulatory authorization?

The Food and Drug Regulations apply to medicinal maggots and leeches that are produced in Canada as well as medicinal maggots and leeches that are imported into Canada. Any importation of these products into Canada must be in compliance with the requirements of one the authorization mechanisms listed above.

Further Questions?

For further information, please contact the Biologics and Genetic Therapies Directorate, Health Canada.

Sponsors interested in filing a submission should contact the Office of Regulatory Affairs, Biologics and Genetic Therapies Directorate, Health Canada.

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