Making a percent solution

Ok all you science guys. What is the proper formula for making a certain percentage solution? Say I want to make a 2% saw palmetto solution as a topical for my scalp. How many mls of solution and how many mgs of saw palmetto should I use? I tried looking this up but it was a bit confusing. Something about using 1 gram (1000 mgs) in 100 mls of solution gives you 1 percent I think. Then you have to figure out different fractions of that for different percentages. I dunno. I might have to ask a pharmacist.

I'd also appreciate an answer. I'm also thinking about making topicals, not necessarily saw palmetto but the science behind it would come in handy nontheless.

I think I found something. It's from this website....
https://sciencing.com/make-five-percent-solution-salt-8076940.html

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Determine Final Volume
Work out how much salt solution you need. For this example, say you need 200 ml of  salt solution.

 
Work out Percentage
Work out 5 percent of 200, i.e., 0.05 × 200 = 10. To make a 10 percent salt solution, work out 10 percent of 200 and so on. You can also work this out by re-arranging the formula, but multiplying the final volume by the decimal form of the percentage is simpler.
   

Weigh Salt
Weigh 10 grams of salt. You can use any type of salt, including table salt.
   

Dissolve Salt
Pour the salt into a graduated cylinder or volumetric flask containing about 180 ml of water. Swirl the flask gently until all the salt dissolves.
   

Add Water
Add enough water to bring the final volume up to 200 ml. Don't simply measure 200 ml of water and add 10 g of salt. Adding salt changes the final volume of the solution and affects the final percentage.
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Something like that.