The pheromone persists until around 23 months; ie, slightly after kittens are weaned.16 It is believed that the production of this pheromone reassures kittens, promotes security and may facilitate bonding between kitten and mother.16.
Pheromone therapy uses synthetic copies of naturally occurring pheromones to help reduce stress, anxiety and other behavioral issues in dogs and cats. Imitation of these pheromones help stimulate feelings of calm and comfort.

Furthermore, visual representations like the one above help us fully grasp the concept of Pheromone Therapy For Kittens.
How long does it take for pheromone therapy to work? It does depend on what the pheromone is being used for. We would recommend using the product for at least a month.

3. Consider Pheromone Therapy. Nature has its way of calming even the most restless souls, and pheromones, which are species-specific chemical signals, tap into this power. Specially formulated products, such as synthetic pheromone sprays or diffusers, mimic the soothing scents...

Pheromone therapy has been studied for over 25 years. When used correctly right placement, consistent use, full 30-day trial most cats show real improvement in fighting, spraying, and anxiety behaviors. This isn't new.