yhteisvaikutuksessaan
Yhteisvaikutuksessaan is a Finnish grammatical form based on the noun yhteisvaikutus, meaning a joint or interaction effect. The word in inessive form indicates “in its joint effect” or “in its interaction,” with an additional third-person possessive suffix to specify ownership. It is used to refer to the combined effect produced by two or more factors, substances, or processes, as opposed to the effect of any single factor alone.
In practice, the term appears in fields such as pharmacology, toxicology, chemistry, and statistics. In pharmacology
Morphology and usage notes: the form combines yhteisvaikutus (joint or interaction effect) with the inessive suffix
Example: Esimerkiksi kahden lääkeaineen yhteisvaikutuksessaan voidaan havaita synerginen vaikutus, jolloin kokonaisvaikutus on suurempi kuin aineiden erikseen.