This is the 12904th most frequent Russian word.
лекарственным
"Лекарственным" means "medicinal" or "relating to medicine."
The word "лекарственным" is used here as an adjective to describe 'effect',' indicating that the effect pertains to medicine or treatment.
Этот крем обладает лекарственным эффектом.
This cream has a medicinal effect.
In this sentence, "лекарственными" modifies 'properties,' implying that the properties are associated with healing or medical applications.
Растение известно своими лекарственными свойствами.
The plant is known for its medicinal properties.
Here, "лекарственное" is related to 'substance,' signifying that the substance has a relation to medicine or is used in treatment.