USP-S | Serum

USP-S | Serum released November 8, 2013 as part of the CS:GO Weapon Case 2.

It originally released during the CS:GO era, before Valve's Counter-Strike 2 relaunch in September 2023 — its artwork, wear range, and source carried over unchanged into CS2.

It launched as a Classified-tier finish, with both a StatTrak™ and a Souvenir edition.

As a finish, "Serum" is applied to the USP-S — the Counter-Terrorists' suppressed sidearm, valued for its accuracy and quiet follow-up shots — and carries the pink rarity color every Classified-tier skin shares on the Steam Market and in-game.

That Classified classification places it one tier below the rarest Covert finishes, but above the more common Restricted-and-below skins most loadouts are filled with.

USP-S | Serum only ships in 3 of the five wear conditions (Factory New, Minimal Wear, Field-Tested) — there's no Well-Worn or Battle-Scarred release for this finish.

As with every CS2 skin, lower float values look cleaner: Factory New copies (roughly below 0.07 float) show the finish at its sharpest, while Field-Tested and Well-Worn pieces make up the most commonly traded middle ground between mint and heavily worn.

USP-S | Serum comes from the CS:GO Weapon Case 2 — the Case is no longer part of the active drop pool, so trading and the Steam Community Market are the ways to acquire it today.

Valve's own published Case odds put a Classified-tier pull like this one at roughly 1 in 63 (1.6000%).

There's both a StatTrak™ and a Souvenir edition of this finish, alongside the Normal version — three ways to own the same look, differing only in that badge.

Beyond that, there's no separate "phase" or pattern family tied to this finish in the site's data — it's tracked as a single fixed look across every wear condition it ships in.

As a Classified-tier finish, USP-S | Serum sits among the more common pulls from the CS:GO Weapon Case 2 rather than being a chase item — a straightforward, affordable way to add an USP-S skin to a loadout or collection.

Its StatTrak™ and Souvenir editions tend to trade at a premium over the Normal version, the same pattern seen across most CS2 skins with that variant available.

USP-S | Serum has been part of the CS:GO Weapon Case 2 since November 8, 2013, and like every CS:GO-era CS2 skin, carried over unchanged when Valve relaunched the game on the Source 2 engine in 2023 — the artwork, wear range, and source Case/Collection are the same today as they were before the migration.

It's one of 2 Classified-tier items in the CS:GO Weapon Case 2, out of 12 items total.

This is one of 44 USP-S skins currently listed on the site, spanning multiple rarity tiers.