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Overview Analysis vs. Month by Month Analysis; Which Do I Need?

One of the most common questions we are asked by our clients is the difference between ‘month by month’ and ‘overview’ analysis.

Once you have chosen to instruct Lextox for hair drug testing, you will need to decide what type of analysis you require. In this blog we aim to clarify the differences between the two and help you choose the most appropriate analysis for your case.


When assigning time periods, at Lextox we use an average growth rate of 1cm per month as per the guidance from the Society of Hair Testing (SoHT). This is an average growth rate meaning that some people’s hair can grow at a faster or slower rate. Therefore, the time periods are quoted as approximate and should not be over-interpreted.

Overview Analysis

An overview analysis will cover a whole 3cm (3 month) section and will identify drugs detected within that approximate 3 month time period. Therefore, an overview of a 6 month drug test will provide you with two results, one for the first 3 months and a second result for the second 3 months. The overview analysis will provide a general result of drugs detected within a 3 month time period, and not to an individual month. This type of analysis is beneficial if you only need to obtain a general indication of whether drugs are detected or not.

Month by Month Analysis

By segmenting scalp hair samples into monthly 1cm sections, a month by month profile of drugs detected can be attained. This is especially useful if you need to obtain a trend in drugs detected, i.e. to see a decrease or increase in drugs detected over time, or highlight intermittent patterns.

As an example; a 3 month section of scalp hair can be broken down into monthly sections to show an individual result covering June, a separate result covering May and another result covering April. Therefore, if a hair drug test was to cover 6 months, a month by month analysis will provide 6 individual results for each approximate monthly period.


If you are looking for a general indication of an individual’s drug use, then an overview analysis should be sufficient. Should you or the court require a more detailed insight into an individual’s pattern or trend of drug use then it is worth opting for month by month analysis.

It is important to bear in mind that Lextox does not offer month by month analysis for the testing of hair alcohol markers. The Society of Hair Testing suggests that EtPa and EtG analysis should be used for the hair strand alcohol test in either a 0-3 cm or a 0-6 cm section, covering approximately the past 3 or 6 months respectively.

Instruct us for hair drug testing today by filling out an online form, calling 029 2048 4141 or emailing [email protected].

Published 23/08/21 – All information correct at time of publication