How reconstitution actually works, step by step, and the two places people go wrong

The mechanics, described rather than prescribed.

**The process as generally described in the literature:**

1. Let a cold vial come to room temperature first. Adding liquid to cold powder can cause condensation and slows dissolution. 2. Disinfect both stoppers and let them dry. Wet alcohol doesn't do the job. 3. Draw the intended volume of diluent. 4. Direct the diluent slowly down the inside wall of the vial rather than jetting it onto the powder. Peptides are shear-sensitive and a direct stream is unnecessarily rough. 5. Let it dissolve. Swirl gently if needed. Do not shake. 6. Look at it. It should go clear.

**Where things go wrong, in order of frequency:**

**Shaking.** Air-liquid interfaces are where peptides unfold. Vigorous shaking creates a lot of them. It also creates foam, which makes accurate drawing harder.

**Volume arithmetic.** Concentration is determined entirely by how much diluent you added. Get that wrong and every subsequent measurement inherits the error. This is where the ten-fold mistakes happen, not in the chemistry.

**On cloudiness:** a solution that stays cloudy, or has visible particulate after adequate time, has not fully dissolved or something is wrong. Clear is the expected end state for most of these.

Evidence tier: general handling practice from pharmaceutical literature, not compound-specific research. Described as what the sources say, not as instruction for anyone.