Try training your arms with different angles, 180 degree, also change the grip of your workouts, from neutral grip, hammer grip, to reverse grip
also these are my best exercises for arms

tricep: dips, close grips press, overhead dumbell press
bicep: straight bar curl, hammer curls and revers grip curls, try changing the angles of the bicep exercises

btw sometimes it's the shape of your arms, genetics sometimes left arm is smaller than other it's genetics the shape insertion of a certain muscle u cant do anything about it

unilateral and more frequent workouts

I have a similar problem, my left calve is noticibly smaller, I'm working on trying to balance out

It could be worse... You could be an arm-wrestler.

Are you sure you're measuring each arm in the same position? If you have defined arms and a decent size tricep, having the tape in the wrong place will throw off your measurement quite a bit. Also do you have tattoos, scars, or anything that you don't have on the other arm? If so, that can make one arm look a different size than the other. The way the light hits one arm over the other can affect your appearance if you're judging yourself by pictures or looking in the mirror.

my left bicep seems to be about half an inch smaller than the right so i have been using dumbells and doing about another 2 reps per set on my left arm and it seems to be working itself out

take Livtropn(HGH) using free weights also what type of isolation exercise is you using free weights should ensure that they grow the same amount remember triceps and biceps use different exercises and different techniques

Hello Sir,

Quite a common problem. Sticking with compounds exercises and growing overall size will eventually solve this problem. A good off season with calorie surplus and compound exercises with progressive overload training will sort this problem.

Regards

You want to compete? No, then fuck symmetry and hit heavy, strict form deadlifts and get massive!

I guarantee you, you're the only person who will notice your wanking arm is bigger than your none wanking arm. Only a few are symmetrical.

On a side note, stop wanking

If you have problems with your arms start train only with free weights and heavy back workouts let your biceps defo grow.

Same by tricep, dips, overhead extensions and close grip bench pressing helps a lot!

I do only 6 sets biceps cause he grows mostly from my hard back workouts! Triceps the same...

Use more dumbbells same weight don’t use different weight
Like 25 on your strong side 30 on your weak side etc don’t do that you’ll make worst than better
Check the position on your bench press you might hitting arm more than chest if your position wrong
Always start with your weak side
Eventually it will be the same
Good luck buddy

Try using more dumbbells so your stronger arm doesn't take more of the weight and do more work.. And again what Sam said hit some extra sets on that side... Sometimes your dominant arm can have better form than your other one also.. try to focus on exact range of motion and form on both.. it will catch up..u ever injure that arm

I too noticed my left arm was about 1/4" smaller than the right. After thinking about it I realized most everything I do at work is with my right arm. So I started forcing myself to carry my tool bag with my left, turning a screwdriver with my left etc... while it is still not exactly the same size ot is getting closer.
Just a thought that may help you figurre it out

Try doing an extra set on the smaller arm. Stay off machines.