Is a SkinVive touch-up ever needed?

Asking about a SkinVive touch-up usually means you want a rule you can follow without going back to the injector. No published figure gives you that rule, and guessing at one is the mistake to avoid.
What the timeline looks like
modernaesthetics.com reports that SkinVive by Juvéderm has results lasting through six months with optimal treatment. That is a timeline for the whole treatment, and it says nothing that would let you decide on your own to add more product between visits.
What "optimal treatment" leaves open
"Optimal treatment" is a condition, and the source does not say what it involves. Whether a touch-up fits your plan is a decision about your skin and your first session, and a reader cannot make it from a headline figure. Do not book extra product elsewhere because a result looks different at week two or week ten.
Questions to take to your injector
Ask what they expect the first treatment to deliver, when they would want to see you again, and what they would check before adding anything. Those answers are specific to you in a way no article is.
Coverage of the approval
The maker's own account is the release on SkinVive by Juvéderm receiving U.S. FDA approval. Dermatology Times reports on the FDA approval of Skinvive by Juvéderm. Two consumer pieces describe it as the new injectable that doubles as skincare and the first injectable of its kind available in the US.
A touch-up decided alone
A touch-up decided on your own, or with someone who did not do the first session, is a decision made without the information that matters most.