There are few things that might happened.
1) The quality of the device might have an inpact whether the laser therapy will be effective. Similarly, ‘maintenance’ of equipment, inspections and its calibration. Sometimes the laser is not correctly selected for a given procedure or patient / client.
Always inquire about the type of laser before starting treatments.
Ask for the year of production and it’s maintenance.
Ask about the manufacturer of the laser – who and where made it.
2) incorrect parameters setting – it may be associated with the lack of knowledge, experience of the operator . Sometimes it happened, when it is not possible to independently adjust: fluency, pulse duration and the size of the treatment spot.
Also, it often results from the lack of patch test, so parameters are not adjusted individually for each patient-client.
Ask about the qualifications of the person performing the treatments, their experience.
Make sure you have a patch test, before the procedure- usually during the consultation.
3) Individual response – and how each individual reacts may have an impact on the effectiveness of the treatment.
4) In the case of therapy that requires a course of treatments, it may be associated with incorrectly selected intervals between treatments.