MK-677 as a PCT: Can You Use Ibutamoren as Post-Cycle Therapy?

Can you use MK-677 as a PCT? No study has tested it, and how it works makes it a poor fit. Post-cycle therapy (PCT) is meant to restart your body’s own testosterone production after SARMs or steroids have suppressed it, which means getting LH and FSH back up. MK-677 raises growth hormone instead; in the one trial that checked, it didn’t change LH or FSH, and in a case report of a man taking it with LGD-4033, testosterone still fell 62% and FSH stayed low after he stopped.

Below: what PCT has to do, what MK-677 does and doesn’t do to your hormones, why the “MK-677 as PCT” idea caught on, and what the evidence-based PCT options are. For the compound itself, see our MK-677 (ibutamoren) review.

What is MK-677?

MK-677 (ibutamoren) is an oral growth hormone secretagogue: it copies the hormone ghrelin and makes the pituitary release more growth hormone (GH), which raises IGF-1 (FDA 2024). It is not a SARM and does not act on the androgen receptor. In human trials it added lean mass and raised appetite and blood sugar (Nass 2008). It has never been approved as a medicine.

MK-677 and PCT

Suppressive cycles hit testosterone at its control center: the hypothalamus and pituitary in the brain, which drive the testes through the hormones LH and FSH. Stopping anabolic steroids is a recognized cause of this “central” hypogonadism (MedlinePlus), and SARM-containing stacks have been documented to push FSH below range (Cardaci 2022) or cause hypogonadotropic hypogonadism (Chong 2024). PCT is about restarting that signaling. The drugs studied for it, such as clomiphene, enclomiphene and tamoxifen, are covered in SARMs PCT and our guides to clomiphene, enclomiphene and tamoxifen (Nolvadex).

MK-677 doesn’t work there. What the evidence shows:

• LH and FSH didn’t move. In obese men given 25 mg/day for 8 weeks, peak LH and FSH were the same as on placebo. Total testosterone was actually lower than on placebo, while the testosterone/SHBG ratio, an index of free testosterone, didn’t change (Svensson 1999).
• It didn’t prevent suppression in a stack. A 25-year-old taking LGD-4033 10 mg with MK-677 15 mg daily for five weeks had total testosterone fall 62%, free testosterone 86% and SHBG 80%. FSH was below the reference range during the cycle and still low afterwards (Cardaci 2022). Most values recovered after he stopped, but MK-677 didn’t stop the suppression from happening.
• No trial. No study has tested MK-677 for recovery after SARMs or steroids.

So “MK-677 as PCT” means using something that doesn’t address suppression during the period when your testosterone is low.

Why people use MK-677 “as PCT”

The idea comes from two real observations. First, MK-677 isn’t suppressive on its own, so it can be taken after a SARM cycle without adding to the shutdown (Svensson 1999). Second, it has anabolic-looking effects that might help hold on to muscle while testosterone is low:

• In 8 dieting adults, 7 days of 25 mg/day turned a negative nitrogen balance positive, meaning less protein breakdown (Murphy 1998).
• In older adults, 12 months of 25 mg/day added 1.1 kg of fat-free mass vs a 0.5 kg loss on placebo, though strength didn’t change (Nass 2008).

Neither study involved people coming off SARMs or steroids. Whether MK-677 preserves muscle after a cycle is untested. The older version of this page cited a study showing people gained “two pounds of muscle” on “12.5 mg for 16 weeks”; the study it linked used 25 mg/day for 12 months and reported 1.1 kg, so we have corrected that.

MK-677 “as a PCT” example: what we removed

An earlier version of this page showed a protocol table running MK-677 through and after a SARM cycle. We have removed it: Sarmguide doesn’t publish personal protocols, and there is no study showing that such a plan restores testosterone. If you are planning recovery after a suppressive cycle, the PCT and bloodwork planner shows what studies cover, and the stack checker flags overlapping risks.

MK-677 side effects to keep in mind

MK-677 adds its own side effects to a post-cycle period: increased appetite (67% vs 36% on placebo), mild swelling and muscle pain, and higher fasting glucose with lower insulin sensitivity (Nass 2008). Trials also recorded raised liver enzymes and higher prolactin in some people, and a heart-failure signal in frail older adults (FDA 2024). In the LGD-4033 case above, liver enzymes and cholesterol worsened during the stack (Cardaci 2022). Full list: MK-677 side effects.

Where to buy MK-677

Product quality varies: in a lab analysis of 44 products sold online as SARMs, only 41% matched their label (Van Wagoner 2017). Look for a batch-specific certificate of analysis from an independent lab. Sarmguide’s current partner shop is SwissChems; our SwissChems review explains why.

Conclusion

MK-677 is not a PCT. It doesn’t raise LH or FSH, it didn’t prevent testosterone suppression when stacked with LGD-4033 in the one documented case, and no study has tested it for recovery. It may help hold on to lean mass, but that hasn’t been tested after a cycle either. If a cycle has suppressed you, the evidence on recovery is about the drugs covered in our SARMs PCT guide, not about MK-677. See also do SARMs lower testosterone?