The first issue is product liability, which means that the product is unreasonably dangerous for its intended use. You must ensure that the product contains no known allergens, which means paying for a laboratory analysis and report.
You may also want to consider obtaining liability insuance, and you definitely want to consider incorporating your business, so that any legal actions that may arise may not find their way to you personally, but are limited to the corporation.
The next issue promotionals may be considered an unlawful deceptive trade practice unless they really are completely free, i.e., absolutely nothing required in exchange for the giveaway. So, for example if you are trying to build a customer base and the lip gloss goes only to those who provide contact info, then you must explain that in detail. And, if there is a limit on the number of free units available, then you must explain that, too.
The next issue is gambling. If there is any element of chance in determining who will receive the lip gloss, then you may be offerring an unlawful lottery, which is criminalized in every jurisdiction (yes, even Nevada).
The next issue is trade dress. If your product have the identical look and feel of something else already being marketed in your locale by a major cosmetics manufacturer, then you could find yourself being sued for confusing or misleading the public and trading off the goodwill of a competitor.
There are probably a dozen things that I've missed, and I am deliberately providing you with the worst possible scenarios so that you are armed to understand the risks involved.
If I had to point to anything in particular as the danger zone it would be failing to incorporate your business, producing a product posing an inherent safety risk, and engaging in an unlawful lottery. But, everything has a risk -- at some point you have to just put your toe in and see what happens.
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