People who smoke high-potency cannabis end up getting higher doses of THC even if they might reduce the amount they puff and inhale to compensate for the higher strength Result: they still take in more THC than smokers of lower potency cannabis.

The idea that high strength cannabis leads to higher doses of THC and therefore poses a greater risk of dependency and other effects has been dismissed by advocates as the 'potent pot myth'. Advocates instead argue that smokers of strong cannabis adjust their drug intake to compensate for the potency, usually by inhaling less smoke or rolling weaker joints.

They even argue that 'super pot' is healthier for cannabis users because they get high while inhaling less lung-harming smoke. 

Dutch researchers observed 98 experienced cannabis smokers as they rolled and smoked joints using their own cannabis samples, which were of varying concentrations. Those who made strong joints inhaled smaller volumes of smoke, presumably in an attempt to titrate the amount of THC taken into the body. But these titration efforts were only partially successful, compensating for roughly half of the THC strength.

So although smokers of strong cannabis alter their smoking behaviour to compensate for the higher potency, they don't alter it enough. There is some truth to the 'potent pot myth'.