{
  "id": "peptide",
  "version": "44e69e2763cd",
  "status": "published",
  "name": "Peptide Calculator",
  "question": "What is my peptide dose in units?",
  "summary": "Does reconstitution arithmetic: the concentration after adding water to a vial, and the mL and syringe units (U-100, U-50, or U-40) for a dose you type. It has no drug presets and suggests no doses.",
  "category": "health",
  "subcategory": "clinical",
  "url": "https://www.acalculator.org/health/peptide-calculator",
  "markdown": "https://www.acalculator.org/health/peptide-calculator.md",
  "kind": "function",
  "method": "Concentration (mg/mL) = vial mg ÷ water mL. Volume (mL) = dose (mg) ÷ concentration. Syringe units = volume × units per mL (100, 50, or 40).",
  "assumptions": [
    "The powder dissolves fully and adds no volume, the usual assumption for small peptide vials.",
    "The dose is the one you were prescribed; the calculator has no drug list and suggests no doses.",
    "Values are rounded for display, halves up; full doses round down."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "mg": {
        "title": "Amount in the vial (mg)",
        "description": "The milligrams of powder in the vial, as printed on the label.",
        "type": "number",
        "minimum": 0.01,
        "maximum": 1000
      },
      "ml": {
        "title": "Water added (mL)",
        "description": "The milliliters of diluent (for example bacteriostatic water) added to the vial.",
        "type": "number",
        "minimum": 0.1,
        "maximum": 100
      },
      "dose": {
        "title": "Dose",
        "description": "Optional: the dose you were prescribed, in the unit chosen below. The calculator suggests none.",
        "type": "number",
        "minimum": 0.001,
        "maximum": 1000000
      },
      "du": {
        "title": "Dose unit",
        "description": "Whether the dose is in micrograms (mcg) or milligrams (mg). 1 mg = 1,000 mcg.",
        "type": "string",
        "enum": [
          "mcg",
          "mg"
        ]
      },
      "syr": {
        "title": "Syringe",
        "description": "The syringe scale: U-100 has 100 units per mL, U-50 has 50, U-40 has 40.",
        "type": "string",
        "enum": [
          "u100",
          "u50",
          "u40"
        ]
      }
    }
  },
  "outputs": {
    "concentration": {
      "label": "Concentration (mg/mL)",
      "description": "Milligrams of peptide in each mL after mixing, to 3 decimals.",
      "format": "number"
    },
    "perUnit": {
      "label": "Per syringe unit (mcg)",
      "description": "Micrograms in one marked unit of the chosen syringe, to 2 decimals.",
      "format": "number"
    },
    "volume": {
      "label": "Volume for the dose (mL)",
      "description": "The mL that hold the typed dose, to 3 decimals. Shown when a dose is typed.",
      "format": "number"
    },
    "units": {
      "label": "Syringe units for the dose",
      "description": "The marked units to draw on the chosen syringe for the typed dose, to 1 decimal.",
      "format": "number"
    },
    "doses": {
      "label": "Full doses in the vial",
      "description": "How many whole doses of the typed size the vial holds.",
      "format": "integer"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "du": "mcg",
      "syr": "u100",
      "mg": 5,
      "ml": 2
    },
    "outputs": {
      "concentration": 2.5,
      "perUnit": 25
    },
    "text": "The mixed vial holds 2.5 mg per mL, which is 25 mcg per syringe unit."
  },
  "examples": [
    {
      "given": {
        "mg": 5,
        "ml": 2,
        "dose": 250,
        "du": "mcg",
        "syr": "u100"
      },
      "expect": {
        "concentration": 2.5,
        "perUnit": 25,
        "volume": 0.1,
        "units": 10,
        "doses": 20
      },
      "source": "StatPearls, Dose Calculation (desired ÷ have × quantity): 5 mg ÷ 2 mL = 2.5 mg/mL; 0.25 mg ÷ 2.5 mg/mL = 0.1 mL; × 100 units/mL (ISO 8537 U-100) = 10 units; 5 ÷ 0.25 = 20 doses (hand calculation in content.mdx)"
    },
    {
      "given": {
        "mg": 10,
        "ml": 3,
        "dose": 500,
        "du": "mcg",
        "syr": "u100"
      },
      "expect": {
        "concentration": 3.333,
        "perUnit": 33.33,
        "volume": 0.15,
        "units": 15,
        "doses": 20
      },
      "source": "10 ÷ 3 = 3.3333 mg/mL; 0.5 × 3 ÷ 10 = 0.15 mL = 15 units; 10 ÷ 0.5 = 20 (hand calculation in content.mdx)"
    },
    {
      "given": {
        "mg": 5,
        "ml": 1,
        "dose": 1,
        "du": "mg",
        "syr": "u40"
      },
      "expect": {
        "concentration": 5,
        "perUnit": 125,
        "volume": 0.2,
        "units": 8,
        "doses": 5
      },
      "source": "5 mg/mL; 1 ÷ 5 = 0.2 mL; × 40 units/mL (U-40) = 8 units; 5 whole doses (hand calculation in content.mdx)"
    },
    {
      "given": {
        "mg": 2,
        "ml": 1.5,
        "dose": 0.25,
        "du": "mg",
        "syr": "u100"
      },
      "expect": {
        "concentration": 1.333,
        "volume": 0.188,
        "units": 18.8,
        "doses": 8
      },
      "source": "2 ÷ 1.5 = 1.3333 mg/mL; 0.25 × 1.5 ÷ 2 = 0.1875 mL, shown 0.188; 18.75 units, shown 18.8 (hand calculation)"
    },
    {
      "given": {
        "mg": 5,
        "ml": 2,
        "du": "mcg",
        "syr": "u50"
      },
      "expect": {
        "concentration": 2.5,
        "perUnit": 50
      },
      "source": "2.5 mg/mL = 2,500 mcg/mL; ÷ 50 units/mL (U-50) = 50 mcg per unit (hand calculation in content.mdx)"
    }
  ],
  "sources": [
    "International Organization for Standardization. ISO 8537:2016, Sterile single-use syringes, with or without needle, for insulin (U-40 and U-100 scales). https://www.iso.org/standard/60510.html",
    "Gage CB, Preuss CV. Dose Calculation. In: StatPearls. StatPearls Publishing; 2023. https://www.ncbi.nlm.nih.gov/books/NBK430836/ (retrieved 2026-09-29)",
    "US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks (retrieved 2026-09-29)"
  ],
  "related": [],
  "changelog": [
    {
      "date": "2026-09-30",
      "note": "Published after this site's editorial review against the cited sources (no clinician review); the page notices say so."
    }
  ]
}