At 4 months post Tickle Lipo, can loose skin be tightened?

It can take up to 6 months for your final results. Non surgical options give only mild improvement compared to surgical lifting, but this will depend on skin laxity. Skin tightening can be done with a combination of Vanquish, Venus Legacy, Exilis, Cellutone/Zwave. However for best results, a tummy tuck can be combined with a high definition procedure at the same time, depending on skin laxity. For best results, I recommend a hi definition procedure like VASER liposuction. I use VASER HI DEF with ThermiRF and Fat Grafting to get the most fat removal, skin tightening, contour and definition. This combination will give you the most toned result. I recommend getting a formal evaluation with a hi definition physique expert. Best, Dr. Emer

Hi Ms PinkFlamingo!  Great questions.  Ain't no replacement for youth and that under 25, never been pregnant, eating right and working out, body!!
We don't know from your question,  what your initial weight/BMI/measurements were, your natural elasticity (ancestry), if there are stretch marks and if your torso was ever larger around previously due to weight or babies?  All those factors can make a difference on the route and manner we suggest to enhance your figure.
Let's assume you were average weight, average exercise, minimal stretch marks, no babies and you were never heavier.  The one liter (about a quart US) of fat that was removed from your mid-section left a deflated space that was initially filled by swelling and inflamed tissue that takes several months to resolve.  Collagen and elastin from any invasive procedure generally take 90-120 days to show visible smoothing and tightening.  At 4 months out, honestly, you are not likely to see a lot more tightening-some, perhaps, but not a lot and the swelling that was masking the deflation has resolved.  Bummer!!
In your ideal world, you might have been offered Laser (SmartLipo and others), Mono-polar Radio Frequency (ThermiRF or BTL) or Helium Plasma (Renuvion) to "shrink wrap" the skin and tissue an additional 10-20% after the fat was sucked/scraped/washed/ from the inside.  If there is a lot of extra skin expected, you might have considered surgically moving the belly button upwards to release the redundant skin and trim the extra-sometimes 3-10 inches tall by 20+ inches across!) from the inferior  abdomen.  That's called a skin excision with umbilical relocation.  If the underlying muscle is tightened at the same time, then we call it an abdominoplasty.  It generally leaves a scar somewhere in the underwear area.
What to do now?  If there is just a bit of extra skin, then external RadioFrequency micro-needling (Profound, Vivace, and others) may be enough to fulfill you skin tightening needs for at least a few years.  If you regain the weight around your middle, that will re-inflate the skin, but if you get thinner as you age, the appearance of extra skin when you sit, may return.
Surgery trades removal of extra skin and stretch marks for a while, but torso skin stretches, the spine looses height over years and abdominal muscles relax and lose volume.  The scar is now part of your wardrobe....so think long term happiness if that is a good trade.
A new technology called EmSculpt causes your abdominal muscles to enlarge without actually doing the exercise yourself.  What would your belly look like if you did 20,000 (yes, 20,000!!) crunches in 30 minutes twice a week for a few weeks?
Hope that gives you something to ponder constructively.  Either way, the fat is probably better gone for your long term health, so something to rejoice about!  Enjoy the journey!
Best, Z