HGH (human growth hormone) dosing depends entirely on why you’re taking it, your body weight, and how your body responds over time. For adults with confirmed growth hormone deficiency, the standard starting dose is 0.15 to 0.30 mg per day, injected under the skin. That’s roughly 0.45 to 0.90 IU per day. From there, your doctor adjusts the dose based on blood work, specifically your IGF-1 levels, which reflect how much growth hormone your body is actually using.
There is no single “right” dose of HGH. The amount that works for one person can cause significant side effects in another. Here’s what the medical dosing looks like across different situations and what to expect during treatment.
Adult Replacement Doses
Adults who don’t produce enough growth hormone on their own typically start at the low end and work up. The recommended starting range is 0.15 to 0.30 mg per day (0.45 to 0.90 IU per day), taken as a single daily injection. Research on young adults with growth hormone deficiency suggests that a replacement dose of roughly 1 to 2 IU per square meter of body surface area per day is adequate for normalizing key biomarkers.
Your doctor will check your IGF-1 levels every few weeks and adjust the dose in small increments. The goal is to bring IGF-1 into a normal range for your age and sex. Some protocols aim for IGF-1 levels in the lower-normal range (around negative 2 to negative 1 standard deviations below the mean), while others target the upper-normal range (1 to 2 standard deviations above the mean). Higher-target dosing tends to reduce body fat more effectively but also increases insulin resistance, so the right target involves trade-offs.
This gradual titration approach replaced the older method of dosing purely by body weight, which frequently led to overdosing and unnecessary side effects.
Pediatric Doses Are Higher Per Kilogram
Children with growth hormone deficiency receive higher weight-adjusted doses than adults because their bodies are actively growing. The standard pediatric range is 0.025 to 0.035 mg per kilogram of body weight per day. For a 30 kg (66 lb) child, that works out to roughly 0.75 to 1.05 mg daily.
Certain conditions call for higher doses. Children with Turner syndrome typically receive about 0.045 to 0.050 mg/kg per day, and those with Prader-Willi syndrome are usually prescribed around 0.035 mg/kg per day. Children with idiopathic short stature, meaning they’re significantly shorter than peers with no identified cause, also fall within these pediatric dosing ranges. These doses are all guided by growth velocity and IGF-1 monitoring, with adjustments made every few months.
Understanding IU Versus Milligrams
HGH dosing can be confusing because some sources use International Units (IU) and others use milligrams. The conversion is straightforward: 1 mg of somatropin equals roughly 3 IU. So a starting adult dose of 0.15 to 0.30 mg per day is the same as 0.45 to 0.90 IU per day. If you see a dose listed in one unit and your prescription uses the other, this conversion lets you compare.
Doses Used for Muscle Wasting
The highest FDA-approved HGH doses are for HIV-related wasting, where the goal is preserving lean body mass in people losing dangerous amounts of weight. These doses are substantially higher than replacement therapy: 0.1 mg per kilogram of body weight per day, with a maximum of 6 mg daily. For someone weighing 75 kg (165 lbs), that’s 7.5 mg per day, more than 25 times a typical adult replacement dose. Most of the effect on lean body mass and physical endurance appeared after 12 weeks of treatment in clinical studies. These doses are not appropriate for people without severe wasting, and there’s no safety data beyond 48 weeks at these levels.
When to Inject
Your body naturally releases its largest burst of growth hormone within minutes of falling into deep sleep during the first part of the night. For this reason, evening injections before bedtime have been the traditional recommendation, since they more closely mimic that natural pattern.
However, recent research has found that morning and evening injections produce comparable effects on growth and IGF-1 levels. Sleep quality, sleep patterns, and daytime alertness are not meaningfully different between the two schedules. The practical takeaway: pick a consistent time that fits your routine. Consistency matters more than the specific hour. Evening still has a slight physiological edge in mimicking your body’s natural rhythm, but morning injections work just as well in terms of results.
What the First Months Look Like
HGH doesn’t produce overnight results. In children, foot growth is often the first visible change, showing up within 6 to 8 weeks. Height gains of 1 to 2 inches typically appear within the first 6 months. Appetite often increases early in treatment, and body composition starts shifting toward more lean mass and less fat, which can make a child look thinner before they look taller.
In adults, body composition changes tend to emerge over 3 to 6 months. You may notice less abdominal fat, more muscle tone, and improvements in energy before any measurable changes show up on blood work. The full metabolic benefits, including improvements in cholesterol and bone density, can take 12 months or longer to develop fully.
Signs Your Dose Is Too High
Side effects from HGH are almost always dose-related, meaning they signal that your dose needs to come down. The most common warning signs include:
- Swelling in your hands and feet (edema): fluid retention is the earliest and most frequent sign of excess dosing
- Joint and muscle pain: particularly in the wrists, knees, and shoulders
- Carpal tunnel syndrome: numbness or tingling in your fingers, especially at night
- Increased insulin resistance: rising blood sugar levels that can progress toward type 2 diabetes if the dose isn’t adjusted
These side effects are more common when doses are started too high or increased too quickly, which is why the modern approach favors starting low and titrating up based on IGF-1 levels rather than body weight alone. If you experience any of these symptoms, your doctor will typically reduce the dose rather than stop treatment entirely.
What HGH Is Legally Prescribed For
In the United States, HGH is a controlled substance that can only be legally prescribed for specific FDA-approved conditions. For children, these include growth hormone deficiency, short stature from being born small for gestational age without catch-up growth by age 2, Noonan syndrome, Turner syndrome, Prader-Willi syndrome, and idiopathic short stature. For adults, the only approved indication is growth hormone deficiency confirmed by stimulation testing.
HGH is also approved for HIV-related muscle wasting. It is not approved for anti-aging, bodybuilding, or general athletic performance, and prescribing it for those purposes is illegal under federal law. HGH is strictly contraindicated in anyone with an active malignancy, with the exception of certain skin cancers. If you have an active cancer diagnosis, HGH therapy is off the table regardless of dose.