Supplies

Bacteriostatic water - not sterile water

These are different products and the difference matters. Bacteriostatic water contains 0.9% benzyl alcohol, a preservative that inhibits bacterial growth, which is what lets a multi-dose vial survive repeated needle entries over weeks. Sterile water has no preservative - it is sterile until the first needle goes in, and then it is a nutrient broth at room temperature.

Use bacteriostatic water for anything you will draw from more than once. Sterile water is for single-use reconstitution only.

The exception worth knowing: benzyl alcohol is contraindicated in neonates, and some people are genuinely sensitive to it. It is also why bacteriostatic water is not used for large-volume administration.

Syringes

For subcutaneous peptide injection, insulin syringes with a fixed needle are the standard choice - the fixed needle means no dead space, so you are not leaving a measurable fraction of a small dose behind in the hub.

One needle, one use. Needles are siliconised and sharpened for a single insertion; a second use is measurably blunter and drags tissue. They cost cents.

The rest of the kit

• Alcohol prep pads (70% isopropyl). Two per injection: one for the vial stopper, one for the skin. Let the skin dry before injecting - alcohol stings when it is carried under the surface, and it has not finished working while it is still wet.
• A sharps container. A rigid, puncture-proof container with a lid. Not a bottle, not a coffee can. Most pharmacies and many municipalities take full ones back. This is the step people skip, and needles in household rubbish injure sanitation workers.
• Refrigerator space, with a thermometer. 2-8 °C. Fridge doors swing much wider than that.
• A log. Date, compound, dose, site, and anything you noticed. Without it you cannot attribute an effect to a cause, and after three months you will not remember.

Storage, honestly

• Lyophilised powder is robust. This is why peptides survive shipping without cold packs. Sealed and dry, most tolerate room temperature for weeks.
• Reconstituted solution is not. Refrigerate immediately, and work on roughly a four-week window unless the compound says otherwise.
• Do not freeze reconstituted peptide. Ice crystal formation and the freeze-thaw cycle degrade peptides. Freezing is for long-term storage of powder, not solution.
• Protect from light and avoid shaking. Swirl gently; aim the water stream at the vial wall rather than directly onto the powder cake.
• Cloudiness, particulates, or a colour change means discard. Clear solutions should stay clear. The one exception is GHK-Cu, which is deep blue by nature - a colourless GHK-Cu solution is the anomaly there.

Injection technique, briefly

1. Wash hands. Swab the vial stopper and let it dry.
2. Draw the dose. Tap out air bubbles and expel them - with subcutaneous injection a small bubble is not dangerous, but it displaces volume and costs you dose accuracy.
3. Swab the site and let it dry fully.
4. Pinch the skin, insert at 45-90° depending on needle length and body fat, inject slowly.
5. Withdraw, apply light pressure. Do not rub.
6. Needle straight into the sharps container. Never recap.

Rotate sites. Abdomen (avoiding a two-inch radius around the navel), outer thigh, upper outer buttock, back of the arm. Repeatedly injecting the same spot causes lipohypertrophy - lumpy, fibrous tissue that absorbs unpredictably, which quietly makes your dosing inconsistent long before it looks like anything.