Guide to Using Peptides

Before you research suppliers, before you buy anything, before you watch another video: book a consultation with a doctor who is comfortable with peptide protocols. This is the single most important step.

• Review your medical history, current medications and family history for contraindications you may not know about: cancer history, thyroid disease, cardiovascular risk, diabetes, hormone-sensitive conditions
• Explain the difference between TGA-approved, TGA-compounded, and research-chemical peptides, and what each means for your legal position and your access to treatment if something goes wrong
• Order the baseline blood work you will need in step 2
• Where appropriate, write a prescription filled by a TGA-licensed compounding pharmacy, which removes the entire supplier-quality problem you would otherwise face

Not every GP is comfortable in this space. Our Doctors directory lists Australian clinics and prescribers who work with therapeutic peptides regularly.

Peptides interact with hormones, glucose metabolism, inflammation markers, and liver and kidney function. You cannot tell whether a protocol is helping or harming you without a before picture.

• Full blood count and iron studies
• Liver function and renal function (eGFR, creatinine)
• Fasting glucose, HbA1c, and for GH-adjacent peptides, fasting insulin
• Lipid panel: total cholesterol, HDL, LDL, triglycerides
• Hormone panel: testosterone (total and free), oestradiol, LH, FSH, prolactin, TSH, free T3/T4, DHEA-S, cortisol
• IGF-1 for growth-hormone peptide protocols
• Inflammatory markers: hs-CRP, ferritin, homocysteine, plus vitamin D, B12, folate

Repeat the same panel 8 to 12 weeks into a protocol so you can see what actually changed. Symptoms lie; blood work does not.

If your doctor has prescribed a compounded peptide, this step is largely done: a TGA-licensed compounding pharmacy is subject to regulatory oversight and its identity is verifiable. If you are buying from an unregulated supplier, which is the reality for most Australian users of research-chemical compounds, then you need to know what you are actually receiving. That is what PepiScreen exists for.

• Do they publish a Certificate of Analysis (COA) for the batch you are being sent? Not just a COA, but the batch number that matches your vial
• Is the COA from an independent, ISO 17025-accredited laboratory (such as Janoshik), or from the manufacturer testing itself?
• Are the retention times on the HPLC chromatogram consistent with the compound being claimed?
• What is their refund policy for wrong product, wrong batch, customs seizure, quality dispute, or non-delivery? Vague answers are a red flag
• How long have they been trading, and what does their reputation history look like?

Ask your prescriber whether they have supplier information they trust, or request a PepiScreen audit to see how a specific supplier scores on Proof, Price, and Match. Already bought from someone? Leave a verified review so future audits benefit from real customer signal.

Most therapeutic peptides are delivered by subcutaneous (SC) injection into the fatty layer under the skin, rather than into muscle. The typical sites are the lower abdomen (staying 5 cm clear of the navel), the outer thighs, and occasionally the back of the upper arm.

• Rotate injection sites daily to avoid tissue irritation and lipohypertrophy (fatty lumps under the skin)
• Clean the site with an alcohol swab and let it dry fully before injecting
• Pinch a fold of skin and insert at 45 to 90 degrees depending on your body composition and needle length
• Draw back slightly to check you have not hit a blood vessel; if blood appears, withdraw and use a different site
• Inject slowly and steadily, then apply light pressure with a clean cotton pad
• Dispose of used sharps in an approved sharps container, never in household waste

Ask your prescribing doctor or a clinic nurse to demonstrate injection technique in person the first time. Videos are a poor substitute for someone watching your first few attempts.

Syringes. The default for most compounded peptides. Insulin syringes (31-gauge, 6 to 8 mm needle, 0.5 or 1 mL barrel) are the standard for SC injection: small, sharp, and marked in units that align with typical peptide doses. Available from any Australian pharmacy without a prescription. Cheap, reliable, and minimal waste when drawing multiple doses from one vial.

Pens. Common for GLP-1 medications (semaglutide, tirzepatide) supplied as branded devices, and also available as refillable systems for compounded peptides. Advantages: consistent dosing, easier to use, less intimidating, more discreet for travel. Disadvantages: higher upfront cost, limited to specific formulations, and pen needles (typically 4 to 5 mm, 32 gauge) are a separate consumable.

Practical guidance. If you are needle-averse, a pen system is worth the extra cost. If you are dosing multiple peptides from separate vials, syringes give you more flexibility. Either way, use a new sterile needle for every injection. Reusing a needle blunts it, hurts more, and raises infection risk.

Sterility is not optional. A subcutaneous abscess from a contaminated injection is a hospital visit; a systemic infection is worse. The rules are simple and non-negotiable.

• Wash your hands thoroughly with soap and water before every injection. This matters more than any other single step
• Use a fresh alcohol swab on the injection site and the vial top each time, and let the alcohol evaporate fully
• Never re-use a needle, even on yourself. Never share needles under any circumstances
• Refrigerate reconstituted vials at 2 to 8 °C unless the specific peptide requires otherwise; check with your pharmacist or the supplier's storage instructions
• Discard any vial that looks cloudy, discoloured, or has visible particles. When in doubt, throw it out; one vial costs far less than one infection
• Track how long a vial has been open. Most reconstituted peptides are stable for about 30 days refrigerated, some less. Write the reconstitution date on the vial

Most peptides arrive as a lyophilised (freeze-dried) powder in a sealed vial and need to be reconstituted with bacteriostatic water (BAC water) or sterile water for injection before use.

• Warm the vial to room temperature if it has been refrigerated (10 to 15 minutes on the bench)
• Wipe both vial tops, the peptide vial and the BAC water vial, with fresh alcohol swabs
• Draw the correct volume of BAC water. The volume sets your dose-per-unit; a common convention is a whole number of mL so the maths stays simple (2 mL into a 5 mg vial means every 40 units on an insulin syringe delivers 1 mg)
• Aim the water at the side of the glass, not directly onto the powder, and release the plunger slowly. Blasting the lyophilised powder can denature the peptide
• Swirl gently until dissolved. Do not shake; shaking creates foam and can damage some peptide structures
• Label the vial with the reconstitution date and the concentration in mg per mL, then refrigerate and use within the stability window

Bacteriostatic water contains a small amount of benzyl alcohol, which lets a vial be used across multiple injections without contamination. Sterile water for injection is single-use only. If you are unsure of the correct reconstitution volume, ask your prescribing doctor or pharmacist. Do not guess.