Evidence-based safety ratings are practical ratings that are standardized throughout Natural Medicines.
Different routes of administration of a product often get different safety ratings. For example, camphor is rated "LIKELY SAFE" when used topically, but it is rated "UNSAFE" when used orally.
This product has a very high level of reliable clinical evidence showing its safe use when used appropriately. Products rated Likely Safe are generally considered appropriate to recommend.
To achieve this Safety Rating a product is supported by all of the following:
Safety data is available from multiple (2+) randomized clinical trials or meta-analysis or large-scale post-marketing surveillance including several hundred patients (level of evidence = A). Or the product has undergone a safety review consistent with or equivalent to passing a review by the Food and Drug Administration (FDA), Health Canada, or similarly rigorous approval process.
Studies have a low risk of bias and high level of validity by meeting stringent assessment criteria (quality rating = A).
Studies adequately measure and report safety and adverse outcomes data and consistently show no significant serious adverse effects without valid evidence to the contrary.
This product has some clinical evidence showing its safe use when used appropriately; however, the evidence is limited by quantity, quality, or contradictory findings. Products rated "Possibly Safe" appear to be safe, but do not have enough high-quality evidence to recommend for most people.
To achieve this Safety Rating a product is supported by all of the following:
Safety data is available from one or more randomized clinical trials, meta-analysis (level of evidence = A or B), case series, two or more population based or epidemiological studies (level of evidence = B), or limited post-marketing surveillance data.
Studies have a low to moderate risk of bias and moderate to high level of validity by meeting or partially meeting assessment criteria (quality rating A or B).
Studies adequately measure and report safety and adverse outcomes data and show no significant serious adverse effects without substantial evidence to the contrary. Some contrary evidence may exist; however, valid evidence supporting safety outweighs contrary evidence.
This product has some clinical evidence showing safety concerns or significant adverse outcomes; however, the evidence is limited by quantity, quality, or contradictory findings. People should be advised NOT to take products with a "Possibly Unsafe" rating.
To achieve this Safety Rating a product is supported by all of the following:
Safety data is available from one or more randomized clinical trials, meta-analysis (level of evidence = A or B), two or more population based or epidemiological studies (level of evidence = B), or limited post-marketing surveillance data. Or multiple, reliable case reports show a potential causal relationship between a product and serious adverse outcome.
Studies have a low to moderate risk of bias and moderate to high level of validity by meeting or partially meeting assessment criteria (quality rating A or B).
Studies adequately measure and report safety and adverse outcomes data and show significant serious adverse effects without substantial evidence to the contrary. Some contrary evidence may exist; however, valid evidence supporting potential safety concerns outweigh contrary evidence.
This product has a very high level of reliable clinical evidence showing safety concerns or significant adverse outcomes. People should be discouraged from taking products with a "Likely Unsafe" rating.
To achieve this Safety Rating a product is supported by all of the following:
Safety data is available from multiple (2+) randomized clinical trials, meta-analysis, or large-scale post-marketing surveillance including several hundred patients (level of evidence = A).
Studies have a low risk of bias and high level of validity by meeting stringent assessment criteria (quality rating = A).
Studies adequately measure and report safety and adverse outcomes data and consistently show significant serious adverse effects without valid evidence to the contrary.
This product has a very high level of reliable clinical evidence showing safety concerns or significant adverse outcomes. People should be discouraged from taking products with an Unsafe rating.
To achieve this Safety Rating a product is supported by all of the following:
Safety data is available from multiple (2+) randomized clinical trials, meta-analysis, or large-scale post-marketing surveillance including several hundred to several thousand patients (level of evidence = A).
Studies have a low risk of bias and high level of validity by meeting stringent assessment criteria (quality rating = A).
Studies adequately measure and report safety and adverse outcomes data and consistently show significant serious adverse effects without valid evidence to the contrary.
There is not enough reliable scientific evidence to provide a Safety Rating.
