What time to take each SARM – Half Lives

The best time to take SARMs depends on the SARMs’ half-life—the time necessary for a compound’s active substance to reduce by half in your body.

Dosages are to be timed precisely with the goal of achieving stable blood serum concentrations based on the compounds’ half-life.

If a SARM has a half-life of 24 hours, it would be ideal to take it at least once every 24 hours. Otherwise, you would experience peaks and valleys, failing to achieve stable blood concentrations of the SARM and somewhat compromising the effects.

Timing for Each SARM

Here is the best time to take each SARM based on the latest clinical data underlining the half-life. For chemicals that have an undefined half-life, I am referencing the administration times from their clinical trials. You will find the corresponding studies to each claim at the bottom of this article by looking at the number in parentheses.

Ostarine (MK-2866)

• Half-Life: 24 hours
• Dosing Frequency: 1x day
• Time of Day: Morning

The best time to take Ostarine is in the morning, the same time every day. We know this based on its half-life, which is clinically proven to be 24 hours. [1]

Ligandrol (LGD-4033)

• Half-Life: 24 – 36 hours
• Dosing Frequency: 1x day
• Time of Day: Morning

The best time to take Ligandrol is in the morning, the same time every day. We know this based on its half-life, which is proven to be 24-36 hours. [2]

Testolone (RAD-140)

• Half-Life: 60 hours
• Dosing Frequency: 1x day
• Time of Day: Morning

The best time to take Testolone is in the morning, the same time every day. We know this based on its half-life, which is proven to be 60 hours. [3]

Andarine (S4)

• Half-Life: Clinically Unclear
• Dosing Frequency: 3x day
• Time of Day:
  • Once in the Morning
  • Once at Noon
  • Once at Night

Preclinical data (animal studies) on Andarine suggests that the half-life in humans is only 4 hours. [1]

But, that estimate is widely considered inaccurate and the real half-life of Andarine is thought to be in the range of 24-76 hours. This is based on thousands of anecdotal reports of experiencing the vision side effects days after their last dose of S4. This suggests the half-life is way longer than 4 hours.

Needless to say, in instances such as S4 where the half-life is not clinically proven, the safest way to ensure stable active substance levels is to split up the dosage across the day ideally on two to three separate occasions.

S-23

• Half-Life: Clinically Unclear
• Dosing Frequency: 2-3x day
• Time of Day:
  • Once in the Morning
  • Once at Noon
  • Once at Night

S-23, just like S4, has an undefined and clinically unknown half-life. It’s never been clinically tested on humans, and its half-life in rats is 11.9 hours. [5]

The half-life in humans can be deduced with a mathematical estimation, or preferably a clinical study.

For the time being, the ideal dosing regimen for S-23 would be to split the dose up and take it on two to three separate occasions throughout the day in order to achieve stable blood serum concentrations.

YK11

• Half-Life: Clinically Unclear
• Dosing Frequency: 2-3x day
• Time of Day:
  • Once in the Morning
  • Once at Noon
  • Once at Night

YK11’s half-life is clinically unknown, so splitting the dose throughout the day would be ideal to achieve stable blood serum concentrations.

LGD-3303

• Half-Life: Clinically Unclear
• Dosing Frequency: 2-3x day
• Time of Day:
  • Once in the Morning
  • Once at Noon
  • Once at Night

LGD-3303’s half-life is clinically unknown. Knowing this, the ideal dosing regimen and best time to take LGD-3303 would be on two to three separate occasions throughout the day in order to achieve stable blood serum concentrations.

ACP-105

• Half-Life: Clinically Unclear
• Dosing Frequency: 2-3x day
• Time of Day:
• Once in the Morning
• Once at Noon
• Once at Night

ACP-105’s half-life is clinically unknown. The ideal dosing regimen for it would be to split the dose into two to three occasions across the day to achieve stable blood serum concentrations.

AC-262536

• Half-Life: Clinically Unclear
• Dosing Frequency: 2-3x day
• Time of Day:
  • Once in the Morning
  • Once at Noon
  • Once at Night

AC-262-536’s half-life is also clinically unknown. The ideal dosing regimen for it would be to split up the dose into two to three occasions across the day to achieve stable blood serum concentrations.

Cardarine (GW-501516)

• Half-Life: 24 hours
• Dosing Frequency: 1x day
• Time of Day: Morning

Clinical data on Cardarine never revealed its half-life; however, all human trials had a once-daily dose schedule. [6]

So, we may conclude that Cardarine has a half-life of around 24 hours, and the best practice would be to follow what has been done in the trials.

Stenabolic (SR-9009)

• Half-Life: Clinically Unclear
• Dosing Frequency: 4x day
• Time of Day:
  • Morning
  • Noon
  • Late Afternoon
  • Night

Stenabolic’s half-life is clinically unknown. The best time to take it would be on multiple occasions throughout the day in order to ensure stable blood serum concentrations at all times.

Ibutamoren (MK-677)

• Half-Life: Clinically Unclear
• Dosing Frequency: 1x day
• Time of Day: Morning OR Night

The terminal half-life of MK-677 is 4.7 hours, with IGF-1 levels remaining elevated for up to 24 hours. Once per day, dosing of MK-677 is a viable frequency of administration across the clinical studies to date. [6]

The timing may vary from morning to night depending on why you’re using MK677. If you’re using it to leverage its fat loss benefits, take it at night so you don’t have to deal with the increase in hunger. Otherwise, take it in the morning.

RU-58841

• Half-Life: 1 hour
• Dosing Frequency: 1x day
• Time of Day: Night (After Showering)

The half-life of RU-58841 was found to be 1 hour in an in vivo study. [4]

GW0742

• Half-Life: Clinically Unclear
• Dosing Frequency: 2-3x day
• Time of Day:
  • Morning
  • Noon
  • Night

GW0742’s half-life is clinically unknown. The best time to take it would be on multiple occasions throughout the day in order to ensure stable blood serum concentrations at all times.

Conclusion

Many of the SARMs and other research chemicals on this list have clinical data and evidence on their half-lives in humans, which makes dosing them at the proper times much easier.

Others, like GW0742, S23, YK11, S4, MK677, ACP-105, AC-262-536, etc., are not as thoroughly researched, and the only data we have on their half-life is preclinical and anecdotal.

Fortunately, thousands upon thousands of users have recorded their personal experiences with them, so we have a good idea of how long their half-life might be, as well as when and how often we should take them.

Sources & References:

1. Selective androgen receptor modulators in preclinical and clinical development
2. The Safety, Pharmacokinetics, and Effects of LGD-4033, a Novel Nonsteroidal Oral, Selective Androgen Receptor Modulator, in Healthy Young Men
3. Abstract P5-11-01 : Phase 1 dose escalation study of a novel selective androgen receptor modulator (SARM), RAD140, in estrogen receptor positive (ER+), human epidermal growth factor receptor 2 negative (HER2-), metastatic breast cancer 
4. Pharmacokinetics and Pharmacodynamics of Nonsteroidal Androgen Receptor Ligands
5. Preclinical Characterization of a (S)-N-(4-Cyano-3-Trifluoromethyl-Phenyl)-3-(3-Fluoro, 4-Chlorophenoxy)-2-Hydroxy-2-Methyl-Propanamide: A Selective Androgen Receptor Modulator for Hormonal Male Contraception
6. The Safety and Efficacy of Growth Hormone Secretagogues

A document I originally made for my clients. A neat map to the sphere of PEDs and supplements.

You'll receive the link and a once-a-week PED-related article in your inbox upon subscribing.