The case for starting Botox early rests on a timing claim. Whether the claim holds depends on what it promises and who is making it.
Cleveland Clinic's prevention claim
Cleveland Clinic describes the approach in a single line: "The idea is to use Botox (botulinum toxin) injections to stop wrinkles from occurring in the first place." Note the verb. The goal is stopping something that has not happened yet, which is a harder promise to check than fixing something you can see.
Two kinds of source on one question
Cleveland Clinic's piece titled Does Preventative Botox Really Work? puts the question in its headline. The MedlinePlus entry on Botox is a general reference rather than an argument about timing. Reading both shows the difference between a source that weighs a claim and one that describes a product.
Prevention versus waiting: the hidden premises
An early-start pitch assumes that prevention is worth the repeated cost of treatment. A wait-and-see view assumes that treating visible lines later loses little. You cannot verify either assumption from a sales conversation, so ask which one the person across the desk is relying on.
A third reading from a dermatology reference
The DermNet topic on botulinum toxin is a reference for the substance itself. Use it for vocabulary, then return to the timing question with that vocabulary in hand. A claim you cannot restate in neutral words is a claim you have not yet understood.
What the early start is meant to prevent
Put this question to whoever proposes the early start: what result is it expected to prevent, and how would either of you know it worked? If the reply names an outcome you could later see in the mirror, the proposal has given you something to check. If the reply is about your age, it has not.
An early start beside a wait-and-see plan
Place the early-start proposal next to a wait-and-see plan and compare them on the same terms. Look at the stated goal, the number of visits implied and what each plan says about stopping. Cleveland Clinic's overview of neuromodulators lists the product family, so a quote that mentions only one brand is worth a follow-up. Calm & Collagen writes from North Fresno and covers Madera County too, and this comparison works for a proposal made in either place.