@Back21970 the more spikey responses are due to the sheer number of times questions like this are asked on this forum, by people who are some combination of ignorant, rude, judgemental, or just plain unpleasant. They use an apparently innocent opening post to then post according to their particular agenda.
As others have said, a simple bit of basic investigation on the internet would reveal the answers to these questions, as would following through with a little bit of critical thinking.
"I have a friend that wants to go on the jabs thinking it’s a quick easy fix and that you don’t need to bother about portion control or exercise.
I reckon that if you believe that then every pound lost will go back on the minute you stop as you’ve made no efforts to change what made you overweight in the first place."
I think your friend would have to be wilfully ignorant to ignore all the information provided by prescribers before, during and after getting a prescription. They would also find that portion control can happen without intending to do so on WLI, as that's part of the effect. If your portions aren't reducing then you are unlikely to lose weight after all! Of course, if you stop a diet and don't continue any changes, then you may regain weight. Exercise isn't vital, there are several posters here who have physical challenges and cannot do much at all in the way of exercise, who have still lost significant amounts of weight. Of course it's beneficial, as with any other diet plan. I wonder if people who start WW/SW or other organised diet groups get told that they need to exercise otherwise it's pointless?
None of that is a reason for your obese friend not to try WLI. Maybe you could show her some information about how WLI work and that portion control is indeed part of the process, as it doesn't remove the body fat on its own.