Which setting penetrates deeper?

I am 35y male with skin type III. I’ve had six sessions (8-10 weeks)on my back and shoulders with I believe 15mm 24J with ok results. I am going ask my practitioner to use 18mm/20J which is the setting many on this forum recommend. Would 15mm/30J penetrate deeper and give better results?

Thanks in advance

20J/18mm gives best results if you can handle it without burning. I’m assuming you are using the GentleLASE with a pulse width of 3.

What machine? Settings are not equivalent among various machines.

If the hair is coarse as well then a Yag laser would go the deepest as they have the deepest penetration of all lasers, but work best on very coarse hair.

Its a GentleLASE. What would be more effective 18mm/20J or 15mm/30J?

Thanks

Larger spot size is always better. So go with 18mm/20J. It’s technically equivalent to 15mm/30J, but 18mm penetrates deeper. Some clinics use the smaller spot size to try to target the finer less deep hairs, but the industry opinions vary on whether this actually makes a difference.