Does HGH build up with daily dosing?

Hardly at all in the model. With a half-life of about 3.5 hours, a daily interval is 5 or more half-lives, so each dose has almost fully cleared before the next one and every dose draws about the same curve. The level is near zero for much of each interval.

Is this chart my actual HGH level?

No. It is a modeled estimate from a published half-life, using the same one-compartment model as the Dose Track app. Real levels vary with body weight, injection site, kidney and liver function and other factors, and only a lab test measures them. It is not medical advice.

HGH Half-Life: Peak and Steady State Chart

Q: When does HGH peak after a dose?

Blood levels peak about 3.5 hours after an injection under the skin, according to Norditropin (somatropin) label. Individual timing varies with the injection site, the amount and the person.

Q: How long does HGH take to reach steady state?

About 17.5 hours of regular dosing at the same amount and interval, which is 5 half-lives. With a half-life of about 3.5 hours, levels reach about 50% of steady state after 3.5 hours and about 90% after 11.6 hours. Changing the dose or interval starts a new climb toward a new steady state.

Q: How long does HGH stay in your system after the last dose?

Roughly 5 half-lives, about 17.5 hours, until about 97% has cleared in the model. Half is gone about 3.5 hours after levels start falling. Real clearance varies from person to person, and a drug can still have effects after levels are low.

Short answer: HGH has a half-life of about 3.5 hours (Norditropin (somatropin) label) and reaches steady state after about 17.5 hours of regular dosing. Levels peak about 3.5 hours after an injection under the skin. With daily dosing it clears almost completely between doses, so levels do not build up.

What do HGH levels look like with daily dosing?

Relative units: 1 on the scale is one full dose. There is no FDA label dose for this use, so the chart shows the shape of the curve, not an amount. Dashed line: 5 half-lives. Change the amount or schedule in the calculator.

When does HGH peak after a dose?

Levels peak about 3.5 hours after an injection under the skin.

How long does HGH take to reach steady state?

With regular dosing at a fixed amount and interval, levels climb toward steady state by the same fraction every half-life, whatever the dose. At a half-life of about 3.5 hours:

Time from the first dose to each share of steady state, HGH (half-life 3.5 hours).
Share of steady state	Half-lives	Time
50%	1	3.5 hours
75%	2	7 hours
90%	3.3	11.6 hours
97% (Dose Track's steady-state rule)	5	17.5 hours

How much do HGH levels swing between doses?

The longer the gap between doses compared with the half-life, the bigger the swing from peak to trough and the less the levels build up. These ratios do not depend on the amount.

Steady-state peak:trough and build-up by dosing interval, HGH, in Dose Track's model.
Interval	Peak : trough	Build-up vs one dose
Daily	29.5 : 1	1.01×
Every other day	over 1,000 : 1	1×
Twice weekly	over 1,000 : 1	1×
Weekly	over 1,000 : 1	1×
Every 2 weeks	over 1,000 : 1	1×

Build-up is the accumulation ratio 1 / (1 − e^−k·τ), with k = ln 2 / half-life and τ the interval.

How long does HGH stay in your system?

After the last dose, about half is gone every 3.5 hours. After 5 half-lives, about 17.5 hours, roughly 97% has cleared in the model.

Where do these numbers come from?

After an injection under the skin, FDA labels give a half-life of about 2 to 4 hours: 2.0 hours in healthy adults (Norditropin), 3.0 hours in adults with growth hormone deficiency (Genotropin) and 3.8 hours in healthy adults (Humatrope). One small Norditropin study in adults with growth hormone deficiency measured 7 to 10 hours. Levels peak about 3 to 6 hours after the dose: about 3 hours (Norditropin) and 4 hours (Humatrope) in healthy adults, and 4 to 6 hours in adults with growth hormone deficiency (Norditropin, Genotropin).

The curve uses the half-life, time to peak, route and bioavailability built into the Dose Track app for HGH, and the same one-compartment model with first-order absorption. These are modeled estimates from published half-lives, drawn with the same one-compartment model as the Dose Track app. Real levels vary from person to person, and only a lab test measures them. This is not medical advice and not a dosing recommendation; dosing decisions belong with you and your prescriber.

Vial sizes and syringe math are in the HGH (Somatropin) guide.

When does HGH peak and reach steady state?