An Old Man at Fifty, A Young Man at Seventy" by V. O. Schwab, Sanford Bennett book ad, The Outlook May 29, 1918 (leaf 32)
The pattern
This still is filed under If-then promise.
Define
A conditional contract: if you do this, you get that. The sentence can be tested against the reader's own case.
Mechanism
Specificity does the persuading. The if names the action. The then names the outcome. Hedging kills it.
Verdict
We can name both the action and the result without adjectives
Why it works
The headline is a perfect paradox that demands explanation. Paired with the indisputable visual proof of the before/after photos, it forces the reader into the copy to discover the secret of this 'fountain of youth'.
Steal this when
You have a dramatic transformation story and need a headline that highlights the contrast between the 'before' and 'after' states.