What Is DHB? Half-Life, Dosing Math & How to Track It

What DHB is and how it works

DHB is short for dihydroboldenone, also commonly called 1-testosterone — a synthetic androgen that is essentially a 5-alpha-reduced boldenone derivative, a saturated form of boldenone, the parent hormone in Equipoise. It is not found naturally in the body at meaningful levels and has no history as an approved pharmaceutical product; it exists almost entirely as a compound produced by underground and research-chemical suppliers, which matters for purity and dosing-accuracy reasons beyond the pharmacology itself.

Because it is already 5-alpha-reduced, DHB cannot be further converted by 5-alpha-reductase into a different, more potent metabolite the way testosterone can — its androgenic activity at the receptor is essentially fixed, similar in concept to how drostanolone (Masteron) behaves. It does not aromatize to estrogen, so estrogen-driven side effects like water retention and gynecomastia are not expected mechanisms of action here.

Because DHB shares testosterone’s exact molecular weight (they are structural isomers), a cypionate ester of DHB carries the same ester-to-hormone weight ratio as testosterone cypionate — about 70% hormone, 30% ester by weight.

Dosing math & the mg/mL trap

DHB is labeled by concentration like any ester-based injectable: volume (mL) = dose (mg) ÷ concentration (mg/mL). Because it is exclusively a compounded or underground product rather than a regulated pharmaceutical one, verifying the actual concentration in a given vial — rather than assuming the label is accurate — is a meaningful part of using the math correctly.

If a weekly total is split across two injections, divide by two before applying the volume formula.

Volume to draw at three reference concentrations (U-100 syringe units in parentheses). Reference numbers for the arithmetic only — the HRT tab of the calculator handles any concentration.

Half-life & what it means for frequency

With the common cypionate ester, DHB’s half-life runs roughly 5–7 days — close to testosterone cypionate’s range — which supports a weekly or twice-weekly schedule. Because DHB is compounded rather than a standardized pharmaceutical product, the specific ester (and therefore the exact half-life) can vary more between sources than it does for a regulated compound.

As with any moderate-length ester, it takes several weeks of consistent injections to reach a steady blood level, and effects and side effects taper off over a similar multi-week window after stopping rather than resolving immediately.

What to monitor & the real risks

DHB is also well known for severe post-injection pain (PIP) — often described as more intense than with most other esters — which is worth flagging on its own as a tolerability and adherence issue, separate from anything a lab panel would catch.

DHB’s risk profile otherwise leans androgenic, similar in shape to Masteron: hair loss in those genetically predisposed and acne are commonly reported skin/hair effects. As a 5-alpha-reduced compound, prostate health is worth a baseline and ongoing conversation.

A lipid panel matters here too — 5-alpha-reduced compounds are generally associated with meaningful HDL suppression — alongside standard hematocrit monitoring and, given HPTA suppression like any AAS, total/free testosterone and LH/FSH if fertility is a concern. Because DHB is not a regulated product, sourcing and verified purity are themselves part of a harm-reduction conversation, separate from the hormone’s own pharmacology.

Frequently asked questions