copyright licensing consumer-protection patents product-liability
Can you start a product line with ingredients used in a different product
<p>Is it legal to literally purchase all of the ingredients in a product and make your own product with minor changes?</p>
<p>Ie; I’m making a hair growing serum but I want to put a small % of Selsun blue (another brand product) in it</p>

<p>It sounds like you're not proposing purchasing the ingredients in Selsun Blue, but Selsun Blue itself. This changes the nature of your question. What you are making is more akin to a derivative work.</p>
<p>First I want to address your use of the ingredients of Selsun Blue.
While the recipe and ingredient list of Selsun Blue is <a href="https://www.copyright.gov/circs/circ33.pdf" rel="nofollow noreferrer">not copyright-able</a>, the means of production and list of ingredients is considered a trade secret. Whether using a derivation of the recipe used by Selsun Blue is a lawful practice depends largely on how you obtained the recipe. You'll want to review 18 U.S.C. § 1831, et seq.
Assuming you obtained the recipe legitimately, your use of ingredients to sell a competing product would seem to be lawful.</p>
<p>However, as you seem to not be using the recipe of Selsun Blue, but the product itself. This becomes extraordinarily tricky. Firstly, you can't use their name in your product's packaging. &quot;This product contains Selsun Blue&quot; for instance, would not be permitted, as their product name is a registered trademark. This would also unlawfully confuse consumers as to the source. Your product can't mimic the trade dress of Selsun Blue, that is, the look and feel of the product. As it literally has the ingredients as a component, you'd have to differentiate your product significantly to ensure you're avoiding even slightly appearing to be the same product. And most importantly, you have to check for patents related to this product. If including Selsun Blue causes your product to infringe on one of their patents, then you cannot proceed least you obtain a licence from the patent owner.</p>
<p>In summary, you cannot trade on the rights of Selsun Blue, whether they be copyright, trademark/trade dress or patent and you can't advertise your product using their trademark.</p>

<p>No  -- unless you also violate their trademark or your version infringes on a patent.</p>

<blockquote>
<p>Is it legal to literally purchase all of the ingredients in a product and make your own product with minor changes?</p>
</blockquote>
<p>Yes, this is perfectly legal.  For example, there are several different brands of salted peanut butter that have the same ingredients, namely ground peanuts and salt.  These brands are not infringing each other's rights.</p>
