The short answer: it depends on which tequila. Clear blanco tequila is relatively low in congeners; aged reposado and añejo have more. And the sugary margarita mix often causes more trouble than the tequila itself.
Blanco vs. aged
Unaged blanco (silver) tequila spends little time in barrels, so it picks up fewer congeners. Reposado and añejo are barrel-aged and sit higher on the congener scale. See how it ranks against other drinks.
It's usually the margarita
Classic margarita mixes are loaded with sugar, and sugary mixers can worsen how you feel the next day. A tequila soda with lime is a gentler pour than a sweet, oversized marg.
100% agave matters
Cheaper mixto tequilas cut agave with other sugars and tend to hit harder. Look for 100% agave on the label.
Drink it smarter
Eat, hydrate, skip the sugar bombs, and pre-load with a Gush. The prevention guide.
Always drink responsibly. This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.